Derivation of feline vaccine-associated fibrosarcoma cell line and its growth on chick embryo chorioallantoic membrane – a new in vivo model for veterinary oncological studies

Feline vaccine associated fibrosarcomas are the second most common skin tumor in cats. Methods of treatment are: surgery, chemotherapy and radiotherapy. Nevertheless, the usage of cytostatics in feline vaccine associated sarcoma therapy is limited due to their adverse side effects, high toxicity and low biodistribution after i.v. injection. Therefore, much research on new therapeutic drugs is being conducted. In human medicine, the chick embryo chorioallantoic membrane (CAM) model is used as a cheap and easy to perform assay to assess new drug effectiveness in cancer treatment. Various human cell lines have different tumors growth on CAM. In veterinary medicine such model has not been described yet. In the present article derivation of feline vaccine associated fibrosarcoma cell line and its growth on CAM is described. The cell line and the tumor grown were confirmed by histopathological and immunohistochemical examination. As far as we believe, this is the first attempt to create such model, which may be used for further in vivo studies in veterinary oncology.     

If you build it,they will learn: A review of models in veterinary surgical education

Surgical skills are learned through deliberate practice, and veterinary educators are increasingly turning to models for teaching and assessing surgical skills. This review article sought to compile and review the literature specific to veterinary surgical skills models, and to discuss the themes of fidelity, educational outcomes, and validity evidence. Several literature searches using broad terms such as “veterinary surgery model,” “veterinary surgical model,” and “veterinary surgical simulator” were performed using PubMed, CAB abstracts, and Google scholar. All articles describing a model created and utilized for veterinary surgical training were included. Other review articles were used as a source for additional models. Commercially available models were found using review articles, internet browser searches, and communication with veterinary clinical skills educators. There has been an explosion of growth in the variety of small animal surgical task trainers published in the last several decades. These models teach orthopedic surgery, ligation and suturing, open celiotomy and abdominal surgery, sterilization surgeries, and minimally invasive surgeries. Some models were published with accompanying rubrics for learner assessment; these rubrics have been noted where present. Research in veterinary surgical models is expanding and becoming an area of focus for academic institutions. However, there is room for growth in the collection of validity evidence and in development of models for teaching large animal surgery, training surgical residents, and providing continuing education to practitioners. This review can assist with evaluation of current surgical models and trends, and provide a platform for additional studies and development of best practices.     

Erythropoietin receptor expression in canine mammary tumor: an immunohistochemical study

Erythropoietin (EPO) is a cytokine primarily involved in the regulation of the erythropoiesis. Recently, it has been demonstrated that EPO and its receptor (EPOR) are expressed in several neoplastic cell lines and solid tumors. Furthermore, in vitro and in vivo studies have shown that EPO could promote human breast carcinoma growth by means of the binding with its receptor, although a clear function for EPO in this setting has not been yet established. While the human medical literature has been accumulating strong evidence on EPO's role in oncogenesis, to date, there are no veterinary reports focusing on such an issue. The aim of the present study was to investigate the immunohistochemical expression of EPOR in canine mammary gland dysplastic and neoplastic lesions. Our results show a weak to moderate EPOR expression in dysplastic glands, being immunoreactivity enhanced as the lesion shows an increasing malignant pattern. On the basis of these findings, this study describes, for the first time, the evidence for EPOR expression in canine mammary gland tumor and suggests a feasible EPO's role for canine mammary tumor progression.     

Leukotriene inhibition in small animal medicine

Leukotrienes are important mediators of inflammatory and allergic conditions in people and are suspected to play an important role in tumorigenesis and tumor growth of several different tumor types. Based on this, researchers are making great progress in identifying novel pharmacologic targets for several human diseases. Leukotriene inhibition has resulted in therapeutic benefit in clinical trials involving people with osteoarthritis, allergic asthma, and atopic dermatitis. Despite this progress and the possibility that leukotriene inhibition may also play an important therapeutic role in veterinary patients, parallel advances have not yet been made in veterinary medicine. This article summarizes leukotriene function and synthesis. It also reviews the published literature regarding potential therapeutic applications of leukotriene inhibition in both human and veterinary medicine, focusing primarily on osteoarthritis, NSAID induced gastrointestinal mucosal damage, allergic asthma, atopic dermatitis, and cancer.     

Pigmented squamous cell carcinoma of the conjunctiva of a horse

Abstract A heavily pigmented tumor was removed from the lateral, perilimbal, bulbar conjunctiva of a bay Thoroughbred horse. Excision was incomplete and the base of the tumor was lasered on the assumption that the tumor was a melanoma. No other ophthalmic lesions were seen. Histology showed the mass to be a pigmented squamous cell carcinoma (SCC). The prognosis and recommended treatment protocols are different for SCC and melanoma. This is, to the best of our knowledge, the first report of an ocular, pigmented SCC in the veterinary literature.     

Immunostimulatory effects of oriental plum (Prunus salicina Lindl.)

The fruit of the plum tree (Prunus salicina Lindl.) has been used as a traditional medicinal food in humans to enhance immunity against infectious agents and to treat cancers. However, limited information exists on the mechanisms responsible for its immune enhancing properties. In this study, the immunostimulatory effects of a methanol extract of plum fruit following methanol evaporation and dissolving in PBS were assessed by in vitro lymphocyte proliferation, tumor cell cytotoxicity, and nitric oxide (NO) production. The crude methanol extract stimulated spleen lymphocyte proliferation and NO production by cultured macrophages, and inhibited the viability of tumor cells, significantly greater than media controls. Sequential gel filtration chromatographic separation of the extract on Sephadex G-25 and Sephacryl S-200 gel filtration columns resulted in a more purified preparation that retained the ability to induce lymphoproliferation, tumor killing, and NO production. These results suggest that Prunus salicina contains immunostimulatory components that potentially may be useful in human and veterinary medicine.     

INVITED REVIEW—NEUROIMAGING RESPONSE ASSESSMENT CRITERIA FOR BRAIN TUMORS IN VETERINARY PATIENTS

The evaluation of therapeutic response using cross‐sectional imaging techniques, particularly gadolinium‐enhanced MRI, is an integral part of the clinical management of brain tumors in veterinary patients. Spontaneous canine brain tumors are increasingly recognized and utilized as a translational model for the study of human brain tumors. However, no standardized neuroimaging response assessment criteria have been formulated for use in veterinary clinical trials. Previous studies have found that the pathophysiologic features inherent to brain tumors and the surrounding brain complicate the use of the response evaluation criteria in solid tumors (RECIST) assessment system. Objectives of this review are to describe strengths and limitations of published imaging‐based brain tumor response criteria and propose a system for use in veterinary patients. The widely used human Macdonald and response assessment in neuro‐oncology (RANO) criteria are reviewed and described as to how they can be applied to veterinary brain tumors. Discussion points will include current challenges associated with the interpretation of brain tumor therapeutic responses such as imaging pseudophenomena and treatment‐induced necrosis, and how advancements in perfusion imaging, positron emission tomography, and magnetic resonance spectroscopy have shown promise in differentiating tumor progression from therapy‐induced changes. Finally, although objective endpoints such as MR imaging and survival estimates will likely continue to comprise the foundations for outcome measures in veterinary brain tumor clinical trials, we propose that in order to provide a more relevant therapeutic response metric for veterinary patients, composite response systems should be formulated and validated that combine imaging and clinical assessment criteria.     

Carboplatin for treatment of a Sertoli cell tumor in a mallard (Anas platyrhynchos)

A 13‐year‐old male mallard was diagnosed with a non‐resectable Sertoli cell tumor involving the left testis. The duck was treated with four doses of single‐agent carboplatin given at 4‐ to 5‐week intervals. Heteropenia, 2 weeks after each treatment, was the acute dose‐limiting toxicity. The tumor reduced in size by 25%, and the duck's clinical condition improved for 12 months. Sertoli cell tumors are rare in birds, and this is the first report, to our knowledge, of attempted chemotherapy treatment in the veterinary literature.     

Histamine: metabolism, physiology, and pathophysiology with applications in veterinary medicine

Objective – To review the human and veterinary literature on histamine physiology and pathophysiology and potential applications for clinical use in veterinary critical care. Data Sources – Human and veterinary clinical studies, reviews, texts, and recent research in histamine receptor and antagonist therapy. Human Data Synthesis – Recent progress in molecular biology has led to a more complete understanding of the enzymes involved in histamine metabolism and histamine receptor physiology. The past decade of research has confirmed the role of histamine in the classical functions (contraction of smooth muscle, increase in vascular permeability, and stimulation of gastric acid secretion) and has also elucidated newer ones that are now under investigation. Data on the roles of histamine in angiogenesis, circadian rhythm, bone marrow regeneration, bacterial eradication, and cancer are emerging in the literature. Newer histamine antagonists are currently in drug trials and are expected to advance the clinical field in treatment of allergic, gastrointestinal, and cognitive disorders. Veterinary Data Synthesis – Veterinary histamine research is directed at identifying the effects of certain pharmacological agents on blood histamine concentrations and establishing the relevance in clinical disease states. Research demonstrates important species differences in regards to histamine receptor physiology and tissue response. Studies in the area of trauma, sepsis, anaphylaxis, allergy, and gastrointestinal disorders have direct applications to clinical veterinary medicine. Conclusions – Histamine plays a key role in the morbidity and mortality associated with allergy, asthma, gastric ulcers, anaphylaxis, sepsis, hemorrhagic shock, anesthesia, surgery, cardiovascular disease, cancer, CNS disorders, and immune‐mediated disease. Histamine antagonism has been in common use to block its adverse effects. With recent advances in the understanding of histamine receptor physiology, pharmaceutical agents targeting these receptors have increased the therapeutic options.     

Training evidence-based veterinary medicine by collaborative development of critically appraised topics

In current veterinary education, skills such as retrieving, critically appraising, interpreting, and applying the results of published scientific studies are rarely taught. In this study, the authors tested the concept of team-based development of critically appraised topics (CATs) in training students in evidence-based veterinary medicine (EBVM). The 116 participants were in their fifth year and attending the clinical rotation at the Clinic for Animal Reproduction. Students developed 18 CATs of varying quality on topics of their choice. Preparing the CATs in teams stimulated discussion on the topic and the quality of the retrieved papers. Evaluation of the project revealed that more than 90% of the students endorsed training in critical appraisal of information in veterinary education. In addition, more than 90% considered the development of CATs an effective exercise for assessing the quality of scientific literature. A provided literature evaluation form was perceived as a useful tool for systematically summarizing a publication's quality. In conclusion, team-based development of CATs during clinical rotations is highly valuable for training in EBVM. Learning and intrinsic motivation seem to be enhanced by creating a situation similar to veterinary practice because the task is embedded into an authentic clinical problem. This approach to clinical training helps to prepare students to integrate evidence from literature into practice.     

Platelet‐Rich Fibrin Constructs Elute Higher Concentrations of Transforming Growth Factor‐β1 and Increase Tendon Cell Proliferation Over Time when Compared to Blood Clots: A Comparative In Vitro Analysis

Objective: To compare the concentration of a representative growth factor (transforming growth factor‐beta [TGF‐β]1) eluted from a platelet‐rich fibrin matrix (PRFMatrix), a platelet‐rich fibrin membrane (PRFMembrane), and a whole blood clot (BC) over time, and to compare the mitogenic effect of the eluents from each construct. Study Design: In vitro study. Sample Population: PRFMatrix, PRFMembrane, and BC (n=4/construct/time point). Methods: Each construct was placed in tissue culture wells containing media for 7 days. The media was collected and replenished on days 1, 3, 5, and 7 and the concentration of eluted TGF‐β1 was measured by enzyme‐linked immunosorbent assay. Canine tendon cells were subjected to additional aliquots of the conditioned media and the amount of cell proliferation compared. Results: The media from both PRFM (PRFMatrix and PRFMembrane) constructs contained significantly more (P≤.026) TGF‐β1 at days 1 and 3 and produced a significant increase (P≤.044) in cell proliferation at all time points compared with the BC. The PRFMembrane media contained significantly more (P≤.05) TGF‐β1 at days 1 and 3 and produced a significant increase (P≤.002) in cell proliferation at all time points compared with the PRFMatrix. Conclusions: Both PRFM constructs are comprised of a dense fibrin scaffold that contains increased concentrations of TGF‐β1 and are capable of increasing tendon cell proliferation over time when compared with a BC. Clinical Relevance: The sustained increase in growth factor availability in PRFM constructs may be beneficial in the healing of biologically compromised tissues.     

Use of a serum-free medium to produce in vitro Neospora caninum and Toxoplasma gondii tachyzoites on Vero cells

Neospora caninum and Toxoplasma gondii are cyst-forming coccidian parasites of human and veterinary clinical relevance. In vitro cultivation of the protozoans using Vero cells is usually performed in order to produce antigenic materials. Quantitative and qualitative comparisons of Vero cells grown in RPMI medium supplemented either with foetal calf serum (FCS), horse serum (HS) or a specific serum-free additive (DefCell) were performed. A serum-free cell culture system used to propagate N. caninum (NC-1 isolate) and T. gondii tachyzoites (Rh stain) were compared with the other two cell culture systems. FCS supplemented media was found to be more effective than the others in promoting Vero cells and N. caninum tachyzoites. However, it was found unable to support adequate T. gondii tachyzoite proliferation. Vero cells, T. gondii and N. caninum tachyzoite production gave similar growth patterns with either HS or DefCell supplemented media. Defcell was considered as a good alternative to supplement culture medium.     

Ki-67 and Vascular Endothelial Growth Factor Expression in Intracranial Meningiomas in Dogs

Background: Tumor proliferation in human intracranial meningiomas can be defined by the reactivity of the monoclonal antibody MIB-1 to the Ki-67 antigen. Vascular endothelial growth factor (VEGF), a pro-angiogenic factor, is a predictive marker for survival of dogs with intracranial meningiomas.
Hypothesis: Ki-67 is expressed in canine intracranial meningiomas and is associated with VEGF expression. Ki-67 expression is a prognostic marker for patient outcome.
Animals: Seventy client-owned dogs with WHO grade I intracranial meningiomas.
Methods: Retrospective study assessing the degree of immunostaining for Ki-67 by MIB-1 and VEGF expression in intracranial meningioma tissue from dogs. MIB-1 Labeling Index (LI) was calculated with Image J NIH-software. Extent, intensity, and distribution of VEGF-expression was assessed semiquantitatively. Cross tabulations with Fisher's exact tests and nonparametric Spearman's rank correlations were performed to identify associations between VEGF expression and MIB-1 LI. Fifteen dogs underwent postsurgical radiotherapy and were included in survival analysis. The effect of MIB-1 LI on survival was examined by Kaplan-Meier and Cox proportional hazards regression procedures.
Results: Ki-67 staining was positive in 91% (64/70) and VEGF expression was detected in 96% (67/70). There was no significant association between VEGF expression and MIB-1 LI. MIB-1 LI was not associated with survival.
Conclusions and Clinical Importance: MIB-1 antibody can be used to document cell proliferation in intracranial meningiomas in dogs, but does not predict outcome. No association between VEGF as a marker of angiogenesis and tumor proliferation was found. Angiogenesis might be a more important predictor of meningioma activity in dogs than is Ki-67.     

Ureteral mast cell tumor in a dog

A 6-year-old, castrated male, mixed-breed dog was diagnosed with partial unilateral ureteral obstruction secondary to a ureteral mass. The ureteral mass was surgically resected, and an ureteroneocystostomy was performed. Histopathology of the ureteral mass was consistent with a poorly differentiated mast cell tumor (MCT). The patient recovered well but was euthanized 5 months postoperatively for central nervous system signs. A choroid plexus tumor was diagnosed during necropsy examination. There was no evidence of recurrence or dissemination of the ureteral MCT. Extracutaneous MCTs are rare in dogs, and primary MCT associated with the urinary tract has not previously been reported in the veterinary literature.     

Delivery of growth factors using gene therapy to enhance bone healing

OBJECTIVE: To review the delivery of growth factors using gene therapy for enhancing long-bone fracture healing. STUDY DESIGN: Literature review. METHODS: MEDLINE and CAB Abstracts literature search (1980-2004). RESULTS: Non-union and infected non-union are relatively common complications of long-bone fractures in human and veterinary patients. Growth factors are cytokines that regulate many cell functions important in fracture healing. Exogenous growth factors can be delivered to the fracture site as recombinant proteins or using gene therapy. Recombinant human bone morphogenetic protein-2 and -7 (rhBMP-2 and -7), in particular, enhance fracture healing in numerous experimental and clinical studies. Some limitations with use of recombinant proteins may be overcome by use of gene therapy. Gene therapy involves delivery of the growth factor gene to cells at the fracture site using a viral or non-viral vector. The gene is then expressed (protein synthesis) by cells at the fracture site. Delivery of the BMP gene to the fracture site using gene therapy has been evaluated in laboratory animal models of non-union, with favorable results and without complications. CONCLUSION: Delivery of growth factors, particularly members of BMP family, to the fracture site using gene therapy may be a method to enhance fracture healing. Use of this technology may improve the prognosis for patients with long-bone fractures. CLINICAL RELEVANCE: Clinical application of gene therapy could improve the prognosis for human and veterinary patients with long-bone fractures, but has not been evaluated clinically.     

Ovarian Fibrothecoma in an Arabian Mare: A Rare Case

The occurrence of ovarian tumors is uncommon in domestic animals. Reports are documented more often in the bitch, mare, and cow. In the mare, granulosa-thecal cell tumor is the most common ovarian neoplasms, and other tumors occur less often. Fibrothecoma is a rare gonadal-stromal tumor of the ovary. There is only one reported case in the veterinary literature. This tumor consists of theca cells and fibrous tissues. The present study describes a rare case of fibrothecoma in a 10-year-old Arabian mare that was presented due to infertility problems. The abnormal left ovary was detected via rectal palpation and ultrasonography. Postoperation study showed a solid tumoral mass that completely replaced the normal ovarian tissues. The tumor was large, firm in consistency, with smooth surface. On the cut surface, the mass was white-gray to yellow with cystic areas containing green gelatinous materials. Microscopic examination revealed the structure was composed of fibroblastic cell producing collagen fibers and theca cells containing lipids. Based on histopathologic features, diagnosis of fibrothecoma was confirmed postoperatively.     

Comparison of glucose concentrations in canine whole blood,plasma, and serum measured with a veterinary point-of-care glucometer

Previous studies have determined that, compared to whole blood, serum or plasma used in a portable blood glucometer (PBG) may provide more accurate results. We investigated the accuracy of a veterinary PBG (AlphaTRAK 2; Zoetis) for the measurement of glucose concentrations in serum, plasma, and whole blood compared to plasma glucose concentration measured by a biochemical analyzer. Blood samples from 53 client-owned dogs were collected. Lin concordance correlation coefficient (ρ_c) and Bland–Altman plots were used to determine correlation and agreement between the results obtained for the different sample types. Glucose concentration in whole blood measured by the veterinary PBG was more strongly correlated with the glucose concentration measured by the biochemical analyzer (ρ_c = 0.92) compared to plasma and serum glucose concentrations (ρ_c = 0.59 and 0.57, respectively). The mean differences between the glucose concentrations in whole blood, plasma, and serum measured by the veterinary PBG and the glucose concentration determined by the biochemical analyzer were 1.0, 6.3, and 6.7 mmol/L (18, 113, and 121 mg/dL), respectively. Our findings suggest that, when using this veterinary PBG, the accuracy of a glucose measurement obtained is higher when using whole blood compared to plasma or serum. Use of whole blood allows for more correct assessment and diagnosis, which are necessary for appropriate therapeutic intervention.     

Canine mast cell tumors

Despite the fact that the mast cell tumor is a common neoplasm of the dog, we still have only a meager understanding of its etiology and biologic behavior. Many of the published recommendations for treatment are based on opinion rather than facts derived from careful studies and should be viewed with some skepticism. Because of the infrequent occurrence of this tumor in man, only a limited amount of help can be expected from human oncologists; therefore, burden of responsibility for progress in predicting behavior and developing treatment effective for canine mast cell tumors must fall on the shoulders of the veterinary profession.