Dietary alpha-lipoic acid supplementation inhibits atherosclerotic lesion development in apolipoprotein E-deficient and apolipoprotein E/low-density lipoprotein receptor-deficient mice.

BACKGROUND: Vascular inflammation and lipid deposition are prominent features of atherosclerotic lesion formation. We have shown previously that the dithiol compound alpha-lipoic acid (LA) exerts antiinflammatory effects by inhibiting tumor necrosis factor-alpha- and lipopolysaccharide-induced endothelial and monocyte activation in vitro and lipopolysaccharide-induced acute inflammatory responses in vivo. Here, we investigated whether LA inhibits atherosclerosis in apolipoprotein E-deficient (apoE-/-) and apoE/low-density lipoprotein receptor-deficient mice, 2 well-established animal models of human atherosclerosis. METHODS AND RESULTS: Four-week-old female apoE-/- mice (n=20 per group) or apoE/low-density lipoprotein receptor-deficient mice (n=21 per group) were fed for 10 weeks a Western-type chow diet containing 15% fat and 0.125% cholesterol without or with 0.2% (wt/wt) R,S-LA or a normal chow diet containing 4% fat without or with 0.2% (wt/wt) R-LA, respectively. Supplementation with LA significantly reduced atherosclerotic lesion formation in the aortic sinus of both mouse models by approximately 20% and in the aortic arch and thoracic aorta of apoE-/- and apoE/low-density lipoprotein receptor-deficient mice by approximately 55% and 40%, respectively. This strong antiatherogenic effect of LA was associated with almost 40% less body weight gain and lower serum and very low-density lipoprotein levels of triglycerides but not cholesterol. In addition, LA supplementation reduced aortic expression of adhesion molecules and proinflammatory cytokines and aortic macrophage accumulation. These antiinflammatory effects of LA were more pronounced in the aortic arch and the thoracic aorta than in the aortic sinus, reflecting the corresponding reductions in atherosclerosis. CONCLUSIONS: Our study shows that dietary LA supplementation inhibits atherosclerotic lesion formation in 2 mouse models of human atherosclerosis, an inhibition that appears to be due to the "antiobesity," antihypertriglyceridemic, and antiinflammatory effects of LA. LA may be a useful adjunct in the prevention and treatment of atherosclerotic vascular diseases.

Platelet aggregation responses in clinically healthy adult llamas.

BACKGROUND: Limited information exists regarding hemostasis in camelids despite the importance of platelet function testing in the accurate identification of platelet disorders. As further importation of llamas to North America is restricted, variability in breeding stock will continue to decrease, potentially leading to an increase in heritable bleeding disorders. OBJECTIVE: The objective of this study was to measure platelet aggregation responses in clinically healthy llamas and provide baseline data to which abnormal platelet function may be compared in the future. METHODS: Blood samples were collected from 39 healthy adult llamas, citrated, and centrifuged to produce platelet-rich plasma (PRP). Within 4 hours of the blood draw, 20 microL of each agonist reagent were added to 180 microL of PRP. Final concentrations of agonists were 2 x 10(-5) M ADP, 0.19 mg collagen/mL PRP, 1 x 10(-4) M epinephrine, and 500 microg arachidonic acid/mL PRP. RESULTS: Llama platelets were most responsive to ADP and collagen, with a maximum percent aggregation (mean+/-SD) of 71.3+/-18.6% and 55.8+/-19% and aggregation rates of 9.5+/-3.9 and 6.7+/-3.7 cm/min, respectively. Llama platelet aggregation in response to epinephrine and arachidonic acid was minimal to absent. CONCLUSIONS: This study is the first of its kind to establish baseline values for platelet aggregation in healthy adult llamas.

Eimeria macusaniensis infection in 15 llamas and 34 alpacas.

CASE DESCRIPTION: 15 llamas and 34 alpacas between 3 weeks and 18 years old with fecal oocysts or intestinal coccidial stages morphologically consistent with Eimeria macusaniensis were examined. Nineteen of the camelids were admitted dead, and 30 were admitted alive. Camelids admitted alive accounted for 5.5% of all camelid admissions during this period. CLINICAL FINDINGS: Many severely affected camelids had signs of lethargy, weight loss, decreased appetite, and diarrhea. Camelids with clinical infection also commonly had evidence of circulatory shock, fat mobilization, and protein loss. Nonsurviving camelids also had evidence of shock, edema, bile stasis, renal insufficiency, hepatic lipidosis, muscle damage, relative hemoconcentration, and sepsis. Postmortem examination frequently revealed complete, segmental replacement of the mucosa of the distal portion of the jejunum with coccidial meronts and gamonts. For 17 of 42 camelids, results of initial fecal examinations for E macusaniensis were negative. TREATMENT AND OUTCOME: Most camelids admitted alive were treated with amprolium hydrochloride, plasma, and various supportive treatments. Fifteen of the 30 treated camelids died or were euthanized. CLINICAL RELEVANCE: Findings suggest that E macusaniensis may be an important gastrointestinal tract pathogen in camelids of all ages. Clinical signs were frequently nonspecific and were often evident before results of fecal examinations for the parasite were positive. As with other coccidia, severity of disease was probably related to ingested dose, host immunity, and other factors. The clinical and herd relevance of positive fecal examination results must be determined.

Histology of the Ovary of the Laying Hen (Gallus domesticus).

The laying hen (Gallus domesticus) is a robust animal model for epithelial ovarian cancer. The use of animal models is critical in identifying early disease markers and developing and testing chemotherapies. We describe the microscopic characteristics of the normally functioning laying hen ovary and proximal oviduct to establish baselines from which lesions associated with ovarian cancer can be more readily identified. Ovaries and oviducts were collected from 18-month-old laying hens (n = 18) and fixed in 10% neutral buffered formalin. Hematoxylin- and eosin-stained sections were examined by light microscopy. Both post-ovulatory follicular regression and atresia of small follicles produce remnant clusters of vacuolated cells with no histological evidence that scar tissue persists. Infiltrates of heterophils are associated with atresia of small follicles, a relationship not previously documented in laying hen ovaries. Because these tissues can be mistaken for cancerous lesions, we present a detailed histological description of remnant Wolffian tissues in the laying hen ovary. Immunohistochemical staining for pancytokeratin produced a positive response in ovarian surface epithelium and staining for vimentin produced a positive response in granulosa cells of follicles. Epithelial cells lining glands of the remnant epoöphoron had a positive response to both pancytokeratin and vimentin, a result also observed in women.

Dietary antioxidants and behavioral enrichment enhance neutrophil phagocytosis in geriatric Beagles.

The study objective was to determine the effects of feeding food enriched in antioxidants and a program of environmental/cognitive enrichment on selected ex vivo assays of inflammatory and immune cells in healthy geriatric Beagle dogs (n=21). Four groups of dogs were tested using a 2 x 2 factorial design. The 2-year longitudinal study included both nutritional (control food or antioxidant-fortified food) and behavioral (normal level or cognitive enrichment) interventions. Behavior enrichment included increased exercise, environmental enrichment, and a series of learning tasks. Phagocytosis of opsonized latex-coated beads by peripheral blood neutrophils was measured by flow cytometry and found to be significantly increased in dogs receiving both dietary antioxidants and cognitive enrichment. Simultaneous stimulation of cells with Con A and suppression with Dex resulted in decreased lymphocyte proliferation in dogs receiving both dietary antioxidants and cognitive enrichment, compared to dogs receiving dietary antioxidants or cognitive enrichment alone. There were no significant differences between the groups of dogs for percentages of CD4 and CD8 T-lymphocyte subpopulations before or after lymphocyte stimulation with Con A. These results support our hypothesis that both dietary antioxidants and behavioral enrichment enhance host defense mechanisms.

Encrusted cystitis secondary to Corynebacterium matruchotii infection in a horse.

A 17-year-old gelding was evaluated because of dysuria, inappetence, and weight loss. Cystoscopy revealed severe mucosal ecchymoses with luminal hemorrhage and accumulations of crystalloid sludge. Analysis of a urine sample revealed isosthenuria, an alkaline pH, pyuria, hematuria, bacteriuria, and numerous calcium carbonate crystals. Histologic examination of bladder mucosa biopsy specimens revealed severe neutrophilic infiltration with mineralization. A diagnosis of encrusted cystitis exacerbated by sabulous urolithiasis was made. A Corynebacterium sp susceptible to penicillin, sulfonamide, and enrofloxacin was cultured from the urine and the bladder mucosa biopsy specimens. The horse was treated with penicillin G potassium, IV, for 5 days, followed by trimethoprim-sulfamethoxazole for 4 weeks. Bladder lavage was performed daily for the first 3 days with a balanced electrolyte solution and dimethyl sulfoxide in an attempt to aid expulsion of necrotic debris and crystalline sludge from the bladder. Molecular phylogenetic analysis based on the 16S rDNA gene sequence was used to identify the isolate and determine its phylogenetic position. Results indicated that the isolate was closely related to Corynebacterium matruchotii. To our knowledge, encrusted cystitis secondary to C matruchotii has not been previously identified in a horse.

Keratinizing ameloblastoma in a 9-month-old llama (Lama glama).

A 9-month-old male llama (Lama glama) was presented because of a rapidly growing mass on the right side of the face. Radiographs revealed a marked expansion of the right caudal face region with bone lysis involving the maxilla and the nasal, lacrimal, zygomatic, and palatine bones. Cytologically, the mass consisted of atypical round to polygonal cells with round nuclei and basophilic cytoplasms that formed acini and rows. Histologically, the mass consisted of anastomosing cords and sheets of neoplastic odontogenic epithelial cells embedded in a loose fibrovascular connective tissue. Single layers of peripheral, polarized, palisading, columnar epithelial cells were seen at the edges of some cords. Within the centers of the cords, epithelial cells showed rapid progression to keratin production. The histologic diagnosis was keratinizing ameloblastoma. Ameloblastomas are neoplasms of odontogenic epithelium that tend to be locally aggressive and can cause substantial destruction of bony structures. Because ameloblastomas do not tend to metastasize, they can be successfully treated by complete surgical excision, performed before extensive bony destruction occurs. Ameloblastoma, although expected to be rare, should be onthe list of differential diagnoses for facial swelling in llamas.

Use of chemotherapy for treatment of a mixed-cell thoracic lymphoma in a horse.

A 4-year-old Oldenburg mare was evaluated because of signs of lower airway disease and subsequently developed bilateral pleural effusion. Neoplastic cells were not identified in the fluid sample obtained via the initial thoracocentesis. A thoracic mass was detected radiographically, but its location prevented collection of a tissue sample. A diagnosis of lymphoma was made on the basis of results of immunophenotyping of pleural fluid specimens. Treatment of thoracic lymphoma in horses has been attempted, but there are limited data regarding chemotherapeutic-induced remission. In this horse, remission was achieved by use of a chemotherapeutic protocol consisting of administration of cytarabine, cyclophosphamide, and prednisolone. No adverse drug reactions were encountered during treatment. Immunophenotyping of cells in specimens of pleural fluid could be used to determine lymphocyte lineage and may be a useful alternative diagnostic modality when morphologic and cytologic examination of tissue specimens obtained via invasive techniques is not feasible.

Postgraduate training programs in veterinary clinical pathology in the United States and Canada (1998 to 2002).

BACKGROUND: Residency and graduate programs in veterinary clinical pathology provide specialized training for board certification and are important pathways to careers in clinical pathology diagnostics, teaching, and research. Information about training opportunities is useful for assessing disciplinary needs, outcomes, and changes, garnering program support, and providing objective data for program evaluation by faculty, trainees, and prospective applicants. OBJECTIVES: The goals of this study were to 1) compile detailed information on the number and types of postgraduate training programs in veterinary clinical pathology in the United States and Canada, 2) describe the goals, activities, strengths, and weaknesses of the programs, 3) assess the desirability of program accreditation and program standards, 4) identify supplemental training opportunities, and 5) evaluate changes in programs, trainees, and faculty 4 years later. METHODS: In July 1998, the American Society for Veterinary Clinical Pathology Education Committee sent a survey to representatives at the 31 schools and colleges of veterinary medicine in the United States and Canada and 31 diagnostic laboratories, private hospitals, and pharmaceutical companies. Survey data were compared with updated information obtained from training program coordinators in November 2002. RESULTS: Survey response rate was 94% for universities, 39% for nonuniversity institutions, and 66% overall. In 1998, there were 20 clinical pathology training programs, including residencies (n=10) and graduate programs combined with residency training (n=10), with 36 total training positions. In 2002, there were 25 training programs (14 residencies, 11 combined), with 52 total positions. The median faculty:trainee ratio was 2.0 in both years. Of 67 faculty members involved in training in 1998, 57 (85.1%) were board-certified in clinical pathology and 53 (79.1%) had DVM/PhD degrees. Net faculty numbers increased by 17 (25.4%) but the median per institution remained at 3.0. Primary program goals were 1) eligibility for and successful achievement of board certification in clinical pathology by the American College of Veterinary Pathologists, 2) proficiency in laboratory diagnostics, and 3) contemporary basic or applied research training. Many programs cited research opportunities, caseloads, and training in hematology and cytology as strengths. Program weaknesses included insufficient funding, too few faculty, and limited training in clinical chemistry and laboratory operations/quality assurance. Trainees completing programs within the past 5 years (n=70) were employed in academia (28.6%), diagnostic laboratories (32.9%), and industry (18.6%). For trainees completing programs between 1999 and 2002 (n=38), these percentages were 52.6%, 21.1%, and 7.9%, respectively. Most (62.5%) respondents supported program standards and accreditation, and 76% supported board review sessions for trainees. CONCLUSIONS: Opportunities for postgraduate training in veterinary clinical pathology increased between 1998 and 2002, with 5 new programs and 16 new training positions. These additions and the increased emphasis on diagnostic proficiency, efforts to strengthen training in clinical chemistry and quality assurance, and continuation of combined PhD-residency programs will help address the perceived need for increased numbers of qualified clinical pathologists in academia, diagnostic laboratories, and industry.

Severe diaphragmatic necrosis in 4 horses with degenerative myopathy.

Severe diaphragmatic necrosis occurred in horses with degenerative myopathy due to polysaccharide storage myopathy (n = 2), nutritional myopathy (n = 1), and vasculitis (n = 1). Blood gas analysis performed in 1 horse indicated development of respiratory acidosis. Respiratory muscle necrosis can be severe in horses with degenerative myopathy and can lead to respiratory failure.

Synthesis and anticoagulant activity of heparin immobilized "end-on" to polystyrene microspheres coated with end-group activated polyethylene oxide.

Thiol groups were introduced to unfractionated heparin (UFH) and end-aminated heparin (HepNH(2)) by reaction with 2-iminothiolane under conditions favoring selective modification of terminal over primary amines. End-thiolated heparin retained anticoagulant activity as shown by the activated partial thromboplastin time (aPTT) and anti-Factor Xa (anti-FXa) assays. Thiolated heparins were linked to pyridyl-disulfide activated poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymers adsorbed to 1.15-mum polystyrene microspheres. Surface loadings were similarly low for each type of thiolated heparin. No anticoagulant activity was observed with aPTT assays of heparinized microspheres, due either to the presence of an insufficient amount of immobilized heparin, or to steric constraints inhibiting the formation of a functional heparin-antihrombin complex. However, immobilized heparin retained substantial anti-FXa activity, with significantly greater activity exhibited by the end-thiolated HepNH(2) than the internally (randomly) thiolated UFH.