Case report: Successful treatment of intestinal leiomyositis in a dog using adjunctive intravenous immunoglobulin.

A 10-year-old spayed female Dachshund presented with abdominal pain and generalized severe ileus. An exploratory laparotomy was performed, confirming a severe ileus of undetermined origin. Multiple intestinal biopsy results confirmed acute intestinal leiomyositis. Immunohistochemistry (IHC) stains confirmed a T-cell predominant inflammatory infiltrate. Intravenous immunoglobulin (hIVIG) was administered prior to immunosuppressive therapy. Within 10 days of hIVIG treatment, functional peristaltic activity returned, and symptoms resolved. Long-term management, including the use of mycophenolate, resulted in sustained functional peristaltic recovery. Further studies are needed to explore the potential benefits of hIVIG treatment in the stabilization phase of this commonly fatal, treatment-refractory disease.

An imminent need for veterinary medical educators: are we facing a crisis?

A potential emerging shortage of veterinary medical educators requires the profession to acknowledge and understand the factors leading to this outcome. Expanding class sizes within existing schools and colleges of veterinary medicine and the expected expansion of new programs seeking AVMA-Council of Education accreditation have heightened the need to address an impending shortage of veterinary medical educators. A solution-oriented approach that accurately projects educator workforce needs and identifies factors contributing to the shortage requires effective collaboration across various partnering organizations to develop innovations in pedagogy and educational delivery methods. The veterinary profession must also identify and reduce disincentives that deter students and post-DVM trainees from pursuing careers in education. Finally, efforts at the state and federal level are critical to advocate for financial support and incentives for expansion of the veterinary medical educator workforce. Through these collective approaches and partnerships, the veterinary medical educator workforce can be strengthened to overcome obstacles for educating the next generation of veterinarians to meet societal needs.

Biosecurity Measures in Clinical Practice.

Hospitalized companion animals have increased susceptibility for hospital-acquired/nosocomial infections. Veterinarians have a responsibility to ensure adequate infection control, biosecurity, and biosafety within veterinary hospitals. Through elimination of pathogens and substitution of hazards, as well as implementation of engineering and administrative controls and the use of personal protective equipment, veterinary teams can dramatically reduce unintentional disease transmission.

Diagnostic bone marrow sampling in cats.

Practical relevance: Hematologic disorders are relatively common in cats, as inflammatory, immune-mediated and infectious diseases have the potential to impact erythroid, myeloid and thrombopoietic lines within the bone marrow. Clinical challenges: Clinicians often benefit from information obtained from bone marrow cytology and histopathology in diagnosing hematologic disorders in feline patients. However, these sampling procedures are ones that many veterinarians are intimidated by and thus not comfortably performing in clinical practice. AUDIENCE: This review, aimed at all veterinarians who treat cats, highlights the reasons a clinician may elect to sample bone marrow, and details the collection of bone marrow for both cytology and histopathology. Potential complications and limitations of each procedure are also reviewed. Evidence base: The collection of bone marrow for cytology and histopathology is not new to feline medicine and several research studies have investigated various sampling modalities in cats. This article offers a comprehensive review of the currently accepted best practices.

Fluid Therapy: Options and Rational Selection.

Administration of appropriate types and volumes of parenteral fluids is of paramount importance when treating sick and debilitated patients, especially those fighting critical illness. Fluid selection and accurate calculations must be performed logically and accurately to maximize positive outcomes. Knowledge of fluid types, as well as the complex relationship of the body's fluid compartments, helps clinicians develop rational fluid therapy plans for their patients.

Hepatocutaneous syndrome in Shih Tzus: 31 cases (1996-2014).

OBJECTIVE: To characterize findings in Shih Tzus with progressive superficial necrolytic dermatitis and degenerative vacuolar hepatopathy consistent with hepatocutaneous syndrome. DESIGN: Retrospective case series. ANIMALS: 31 Shih Tzus. PROCEDURES: Medical records were reviewed to obtain information on signalment, history, treatment, outcome, and results of clinicopathologic testing, abdominal ultrasonography, and histologic examination of skin and liver specimens. A pedigree analysis was performed. RESULTS: There were 16 males and 15 females. Median age at the time of diagnosis was 8 years (range, 5 to 14 years). Common clinical signs included lethargy, inappetence, weight loss, and lameness. Twenty-five dogs had cutaneous lesions consistent with hepatocutaneous syndrome; the remaining 6 initially only had hepatic abnormalities, but 3 of the 6 subsequently developed cutaneous lesions. Common clinicopathologic abnormalities included microcytosis (15/24 [63%] dogs) and high serum alkaline phosphatase activity (24/24 [100%] dogs). Hepatic ultrasonographic findings included a hyperechoic or heteroechoic appearance to the parenchyma with innumerable hypoechoic nodules. Histologic hepatic lesions consisted of degenerative vacuolar (glycogen and lipid) hepatopathy associated with minimally fibrotic to nonfibrotic, noninflammatory, proliferative nodules. Pedigree analysis confirmed a common ancestry in 12 of 18 dogs. Median survival time was 3 months (range, 1 to 36 months). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that HCS may have a heritable component in Shih Tzus, although the condition may also be identified in Shih Tzus without affected relatives. Clinical, clinicopathologic, ultrasonographic, and histologic abnormalities in affected Shih Tzus were similar to those previously reported for dogs of other breeds with HCS.

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.

Ostéodystrophie fibreuse préopératoire et hypocalcémie grave, réfractaire postopératoire après une parathyroïdectomie chez un chien. Un chien âgé de 13 ans a manifesté une ostéopénie radiographique dramatique conforme à une ostéodystrophie fibreuse secondaire à un hyperparathyroïdisme primaire. Après une parathyroïdectomie, le chien a développé une hypocalcémie grave et prolongée, mais il a été traité avec succès et a reçu son congé 32 jours après la chirurgie. Divers facteurs peuvent avoir contribué à l'hypocalcémie de ce chien, y compris l'hypoparathyroïdisme et l'hypocalcémie par avidité osseuse.(Traduit par Isabelle Vallières).

Enhancement of dynamin polymerization and GTPase activity by Arc/Arg3.1.

BACKGROUND: The Activity-regulated cytoskeleton-associated protein, Arc, is an immediate-early gene product implicated in various forms of synaptic plasticity. Arc promotes endocytosis of AMPA type glutamate receptors and regulates cytoskeletal assembly in neuronal dendrites. Its role in endocytosis may be mediated by its reported interaction with dynamin 2, a 100 kDa GTPase that polymerizes around the necks of budding vesicles and catalyzes membrane scission. METHODS: Enzymatic and turbidity assays are used in this study to monitor effects of Arc on dynamin activity and polymerization. Arc oligomerization is measured using a combination of approaches, including size exclusion chromatography, sedimentation analysis, dynamic light scattering, fluorescence correlation spectroscopy, and electron microscopy. RESULTS: We present evidence that bacterially-expressed His6-Arc facilitates the polymerization of dynamin 2 and stimulates its GTPase activity under physiologic conditions (37°C and 100mM NaCl). At lower ionic strength Arc also stabilizes pre-formed dynamin 2 polymers against GTP-dependent disassembly, thereby prolonging assembly-dependent GTP hydrolysis catalyzed by dynamin 2. Arc also increases the GTPase activity of dynamin 3, an isoform of implicated in dendrite remodeling, but does not affect the activity of dynamin 1, a neuron-specific isoform involved in synaptic vesicle recycling. We further show in this study that Arc (either His6-tagged or untagged) has a tendency to form large soluble oligomers, which may function as a scaffold for dynamin assembly and activation. CONCLUSIONS AND GENERAL SIGNIFICANCE: The ability of Arc to enhance dynamin polymerization and GTPase activation may provide a mechanism to explain Arc-mediated endocytosis of AMPA receptors and the accompanying effects on synaptic plasticity.

Health perceptions and levels of attachment: owners and pets exercising together.

BACKGROUND: Obesity is a parallel problem in canine and human populations. We describe health perceptions and levels of companion animal attachment in a cohort of dog owners. METHODS: As part of a larger trial examining the impact of veterinary counseling on activity levels of dog owners and their pets, owners presenting to a veterinary referral center were asked to self-report perceived levels of health and attachment to their dog (Lexington Attachment to Pets Scale). Owner body mass index and the body conditioning score of the companion dog were also recorded. RESULTS: Heavier pet owners reported a greater sense of attachment to their dogs. Heavier owners also reported lower perceived health and less social support. CONCLUSIONS: Increasing body mass index is associated with higher pet attachment, lower perceived health, and less social support. This information can impact wellness counseling for overweight pet owners and canine companions.

Thermal injury.

This article addresses the pathophysiology of thermal burns, focusing on the complex inflammatory component, potential complications, and treatment strategies.

Pulmonary thromboembolism.

Pulmonary thromboembolism (PTE) has been associated with many diseases. Clot formation is a consequence of hypercoagulability, blood stasis, and damage to the endothelium of blood vessels, a set of changes known as the Virchow triad. Diagnosing PTE may be difficult because common clinical signs, including tachypnea, dyspnea, and hypoxemia, are not pathognomonic for the disease. The initial workup for PTE should include arterial blood gas analysis and thoracic radiography. If there is a strong clinical suspicion for PTE, further tests are indicated, such as D-dimer measurement, thromboelastography, and advanced imaging.

Determination of threshold adverse effect doses of percutaneous VX exposure in African green monkeys.

Percutaneous exposure to the chemical warfare nerve agent VX was evaluated in African green monkeys (n=9). Doses of VX (7.5-100 µg/kg) were applied to the skin for 60 min and residual agent was quantified (before decontamination) to estimate the absorbed dose. Monkeys were evaluated for the presence or absence of clinical signs of toxicity and blood was sampled periodically (30 min--12 weeks) following exposure to measure the degree of circulating acetylcholinesterase (AChE) inhibition. Monkeys were also evaluated for behavioral changes from VX exposure using a serial probe recognition (SPR) task. The lowest observable adverse effect level (LOAEL) for the production of major clinical signs was determined to be 42.22 µg/kg (absorbed dose estimate=17.36 µg/kg) and the LOAEL for AChE inhibition was 13.33 µg/kg (absorbed dose estimate=6.53 µg/kg). Behavioral performance was unaffected at doses that, while producing substantial AChE inhibition, did not produce clinical signs. VX represents a substantial threat as a contact hazard and these results complement previous studies using the percutaneous route of exposure with VX and extend the findings to a non-human primate species.

Dynamin 2 mutants linked to centronuclear myopathies form abnormally stable polymers.

Mutations in the dynamin 2 gene have been identified in patients with autosomal dominant forms of centronuclear myopathy (CNM). Dynamin 2 is a ubiquitously expressed approximately 100-kDa GTPase that assembles around the necks of vesiculating membranes and promotes their constriction and scission. It has also been implicated in regulation of the actin and microtubule cytoskeletons. At present, the cellular functions of dynamin 2 that are affected by CNM-linked mutations are not well defined, and the effects of these mutations on the physical and enzymatic properties of dynamin have been not examined. Here, we report the expression, purification, and characterization of four CNM-associated dynamin mutants. All four mutants display higher than wild-type GTPase activities, and more importantly, the mutants form high order oligomers that are significantly more resistant than wild-type dynamin 2 to disassembly by guanine nucleotides or high ionic strength. These observations suggest that the corresponding wild-type residues serve to prevent excessive or prolonged dynamin assembly on cellular membranes or inappropriate self-assembly in the cytoplasm. To our knowledge, this report contains the first identification of point mutations that enhance the stability of dynamin polymers without impairing their ability to bind and/or hydrolyze GTP. We envision that the formation of abnormally large and stable complexes of these dynamin mutants in vivo contributes to their role in CNM pathogenesis.

A rapid and sensitive technique for assessing exposure to VX via GC-MS-MS analysis.

A rapid and sensitive method for the determination of the chemical warfare agent VX in plasma taken from Göttingen minipigs has been developed using isotope-dilution gas chromatography-tandem mass spectrometry (GC-MS-MS). Chromatographic separation was achieved on a 5% diphenyl/95% dimethyl polysiloxane capillary column with a total run time of about 11 min. The analyte was detected using ammonia chemical ionization in the multiple reaction monitoring mode, following a simple extraction with 10% 2-propanol in hexane. A good linear relationship was obtained in the quantitative concentration range of 10 ng/mL to 1000 ng/mL (r(2) = 0.9998) with an average slope of 1.275 +/- 0.037 (n = 7), and an absolute detection limit of 0.4 pg on column. The average recovery for VX was 95% in saline in the concentration range of 50-100 ng/mL. The method was successfully applied to the analysis of VX in minipig plasma in a preliminary toxicokinetic study.

Determination of VX-G analogue in red blood cells via gas chromatography-tandem mass spectrometry following an accidental exposure to VX.

A sensitive method for determining exposure to the chemical warfare agent VX is described in which the biomarker ethyl methylphosphonofluoridate (VX-G) is measured in red blood cells (RBCs) following treatment with fluoride ion using isotope-dilution gas chromatography-tandem mass spectrometry. The analyte was isolated via solid-phase extraction and detected using ammonia chemical ionization in the multiple reaction monitoring mode. A good linear relationship was obtained in the quantitative concentration range of 4 ng/mL to 1000 ng/mL with an absolute detection limit of < 1 pg on column. The method has been applied to the analysis of RBCs from a laboratory worker accidentally exposed to VX vapor. Detection and quantitation of VX-G were possible in samples taken as late as 27 days following exposure.