Amanda J. Fales-Williams

Fibrosing gastrointestinal leiomyositis as a cause of chronic intestinal pseudo-obstruction in an 8-month-old dog.

An 8-month-old, female, mixed-breed dog presented to the Iowa State University Veterinary Teaching Hospital with a 1-month history of vomiting and diarrhea. An exploratory laparotomy was performed revealing markedly distended and fluid-filled small and large intestines that were not obstructed. The clinical condition of the dog did not improve subsequent to exploratory surgery, and it was euthanized. At necropsy, both the small and large intestines were distended (approximately 4 cm in diameter) and fluid-filled, and the wall was thin. The abdominal cavity contained approximately 500 ml of a brownish clear fluid. Microscopic lesions of the intestines were confined to the intestinal tunica muscularis and muscularis mucosae and consisted of locally extensive-to-diffuse replacement of the smooth muscle by fibrous tissue and multifocal infiltration by a moderately dense mononuclear inflammatory infiltrate. A unique finding was the presence of similar microscopic lesions in the tunica muscularis of the urinary bladder and stomach.

Cellular Distribution of Anionic Antimicrobial Peptide in Normal Lung and during Acute Pulmonary Inflammation

Anionic peptides (APs) are small antimicrobial peptides present in human and ovine lung. In this study APs were also detected in bovine lung, and production of APs in lungs with acute inflammation induced by various stimuli was determined. The distribution and intensity of APs were determined by immunohistochemistry in lungs of 1) neonatal calves (1-3 days of age) inoculated with Mannheimia (Pasteurella) haemolytica, a known inducer of the bovine β-defensin lingual antimicrobial peptide (LAP) or pyrogen-free saline (PFS), and 2) growing calves (3 months of age) similarly inoculated with M. haemolytica, a lipopolysaccharide (LPS) from M. haemolytica, an LPS-associated protein from M. haemolytica, or PFS. APs were also detected by western blots with the same antibody in lungs of the calves above, as well as in calves inoculated with Pseudomonas aeruginosa, and an adult cow. Anionic peptide (AP) immunoreactivity was detected in bands (approximate weights) in the western blots of lung at 28-30 (strongest signal), 31, 45, and 52-60 kd regardless of inoculum. The adult cow lacked bands at 45 kd, but it had additional bands at 64 (inconsistently) and 35-38 kd. All these band sizes are consistent with those of the western blots of human and ovine lung. The cellular distribution of APs in lung of neonatal and growing cattle was similar to that in lung of human and sheep. In lungs with acute inflammation induced by live bacteria, LPS, or protein, AP distribution and intensity were similar to those in control (PFS-inoculated) lungs and slightly decreased in bronchioles. This work demonstrates that AP is present in lung of cattle and is thereby conserved among two ruminant species and man. Distribution and intensity of AP production are not enhanced by infection or acute inflammation and are decreased in bronchioles, which suggests that AP is not induced like β-defensins such as LAP, but, instead, is produced constitutively.

Increased Anionic Peptide Distribution and Intensity during Progression and Resolution of Bacterial Pneumonia

ABSTRACT Anionic peptides (APs) are small anionic antimicrobial peptides composed of 7 aspartic acid residues and are produced in the lungs of humans, sheep, and cattle. Although expression by epithelial cells of some antimicrobial peptides (e.g., β-defensins) of humans and ruminants is increased in response to acute infection, AP expression is not increased during acute infection, which suggests that the expression of the latter peptide is constitutive. In this study, the degree of AP expression during the progression (acute, subacute, and chronic) of bronchopneumonia was determined. Mannheimia (Pasteurella) haemolytica, a known inducer of bovineβ-defensins, was inoculated intrabronchially with a fiber-optic bronchoscope in nine 3-month-old sheep, and tissues were collected at 1, 15, and 45 days postinoculation (p.i.); nine control animals received pyrogen-free saline by the same procedure and were killed at the same time points. In the acute group (1 day p.i.), the lungs had lesions typical of bronchopneumonia and the distribution and intensity of AP immunoreactivity (AP-IR) were similar to those of previous studies (minimal intensity and distribution of AP-IR in bronchiolar epithelial cells). In the subacute group (15 days p.i.), there was prominent hyperplasia of bronchiolar and alveolar epithelial cells, and the chronic group (45 days p.i.) had yet more pronounced hyperplasia. In the subacute and chronic groups, the intensity and distribution of AP-IR in the cytoplasm of hyperplastic bronchiolar and type II alveolar cells were significantly increased compared to those of saline-inoculated and contralateral (noninoculated) lung lobes. Although AP expression appears constitutive, the constitutive production of AP is higher in hyperplastic, less differentiated cells than in fully differentiated, mature cells of the respiratory airways. The increased intensity and distribution of AP-IR in immature (hyperplastic) epithelial cells may be a mechanism by which production of a noninducible antimicrobial is increased temporarily during lesion progression and repair. This increased production of AP by hyperplastic cells may protect the lung against further infection until new, fully differentiated epithelial cells are capable of expressing their own inducible array of antimicrobial peptides.

Surveillance of amyloidosis and other diseases at necropsy in captive trumpeter swans (Cygnus buccinator)

The purpose of this study was to characterize the incidence and diagnostic features of amyloidosis and other diseases found at necropsy in captive trumpeter swans (Cygnus buccinator). A search of Iowa State Universitys Department of Veterinary Pathology and Veterinary Diagnostic Laboratory databases yielded 31 trumpeter swan (C. buccinator) necropsy cases from captive swans in protected habitats. Eleven of the 31 birds had amyloid deposition most commonly in the spleen (8 of 11), liver (7 of 11), and kidney (6 of 11) and less often in the pancreas (2 of 11) and adrenal gland (2 of 11). Amyloid deposition effaced normal tissue with adjacent necrosis and hemorrhage in severe cases. Amyloidosis was most often diagnosed in February and March. Other disease diagnoses in the trumpeter swans included aspergillosis (5 of 31, 16%); bacterial infection (5 of 31, 16%); lead toxicosis (3 of 31, 10%); gout (2 of 31, 6%); parasitic infection (2 of 31, 6%); vitamin E deficiency (1 of 31, 3%); trauma (1 of 31, 3%); and ventricular foreign body (1 of 31, 3%). Histopathologic, toxicologic, and microbiologic analyses did not define an etiologic diagnosis in the deaths of 9 trumpeter swans. In these cases, necropsy lesions included emaciation (5 of 9), enteritis (1 of 9), pulmonary hemorrhage (1 of 9), and no lesions (3 of 9). The number of trumpeter swan case submissions was greatest in January and February. This study provides a reference for veterinary diagnosticians concerning incidence and diagnostic features of amyloidosis and other diseases in captive trumpeter swans of the midwestern United States.

Idiopathic Arterial Medial Calcification of the Thoracic Arteries in an Adult Horse

A 6-year-old, gelded, Paint horse displayed clinical signs of muscle wasting and limb stiffness for a 6-month period. The horses clinical signs abated with corticosteroid therapy, but returned upon cessation of treatment. Upon necropsy, severe lesions of aortic thickening and aortic valve rigidity were observed. Histologically, the tunica media of the aorta, coronary arteries, and pulmonary arteries were expanded by foci of elastin fiber calcification and extracellular matrix with lacunae formation. The vascular lesions are comparative to what has been described as medial arterial calcification, seen in humans suffering from chronic renal failure or diabetes mellitus. No exposure to vitamin D-containing plants or feedstuff could be documented at the time of onset or during the period of clinical signs. The current case describes dramatic lesions of arterial medial calcification of the aorta, coronary, and pulmonary arteries of undetermined cause.

Evidence of Oxidative Injury of the Spinal Cord in 2 Horses With Equine Degenerative Myeloencephalopathy

The cervical spinal cords of 2 horses with equine degenerative myeloencephalopathy (EDM) were evaluated for evidence of oxidative damage to the central nervous system (CNS) using immunohistochemical staining for 3-nitrotyrosine (3-NT) and 4-hydroxynonenol (4-HNE). Neurons of the CNS from horses with EDM had positive immunohistochemical staining, whereas control samples did not, thus supporting the theory that oxidative damage is a potential underlying factor in horses with EDM. In addition, serum vitamin E concentration was low in both EDM-affected horses, and vitamin E concentration was also deficient in the cerebrospinal fluid in 1 EDM horse, further supporting the association between low vitamin E concentrations and oxidative damage to the CNS. Continued research is necessary to further define the pathophysiologic mechanisms of EDM.

RETROSPECTIVE EVALUATION OF CASES OF NEOPLASIA IN A CAPTIVE POPULATION OF EGYPTIAN FRUIT BATS (ROUSETTUS AEGYPTIACUS)

Reports of neoplasia in Chiroptera species are rare. (6, 10) This retrospective study describes five types of neoplasia identified within a captive population of male Egyptian fruit bats (Rousettus aegyptiacus) housed in a zoo from 2004 through November of 2014. Tumor types identified include fibrosarcoma, cutaneous lymphoma, benign focal bronchioloalveolar neoplasm, anaplastic sarcoma, and sebaceous epithelioma. To the authors knowledge, aside from a recent report of focal brochioloalveolar adenoma, (8) these tumor types have not previously been described in the Rousettus species, nor in chiropterans in general. Based upon these findings and other recent publications regarding R. aegyptiacus, neoplasia does appear to be a significant cause of morbidity and mortality in captive members of this megachiropterid species.

Equine Placental Mixed Germ Cell Tumor With Metastasis to the Foal

The placenta from an embryo transfer–recipient mare and live foal was examined. The placenta was effaced by multifocal masses, which ranged from less than 1 cm to 14 cm in diameter. The foal represented at 52 days for lethargy, ataxia, and urine dribbling; due to a poor prognosis, the foal was euthanized. At necropsy, the liver was effaced by multifocal, pale, irregular nodules. The lumbar vertebrae and other skeletal sites had multifocal lytic lesions. The placenta had 4 populations of neoplastic cells, including a spindle cell population, tall columnar and transitional epithelial cell populations, and an undifferentiated polygonal cell population. The foal’s liver had similar populations and patterns of cells as those in the placenta. The lesion in the placenta and the masses in the foal were diagnosed as a mixed germ cell tumor and metastatic mixed germ cell tumor, respectively.

Undergraduate Rigor Scores: Do They Predict Achievement in Veterinary School?

The relations between potential indicators of undergraduate rigor and subsequent achievement in professional school are not clear; some studies have shown that greater undergraduate selectivity is associated with greater achievement in medical science programs, while others have not. We sought to determine the extent to which indicators of undergraduate rigor were associated with achievement in veterinary school. Participants were graduates from three cohorts. The predictors were undergraduate GPA (UGPA), plus five rigor scores-degree or number of undergraduate credits, number of honors courses, number of withdrawals from or repeats of prerequisite science courses, number of part-time semesters, and ratio of community college credits to total college credits. The outcomes were the veterinary medicine cumulative GPA (CVM GPA), Qualifying Exam scores, and North American Veterinary Licensing Exam scores. Using correlations corrected for range restriction, we regressed each outcome on the five rigor scores and UGPA for each of the three graduating cohorts. In most cases, indicators of undergraduate rigor did not predict subsequent achievement in veterinary school; however, in two comparisons, number of honors courses taken as an undergraduate predicted subsequent achievement. UGPA, as expected, predicted CVM GPA. Admissions committees may want to reevaluate whether they include undergraduate rigor when considering admission to their programs, with the caveat that our findings are specific to our institution and are not generalizable.