Outcome of a dog undergoing definitive-intent intensity-modulated radiation therapy for an intranasal ganglioneuroma.

An 11-year-old intact male Shiloh Shepherd was presented for evaluation of epistaxis, decreased nasal airflow, and destructive caudal nasal lesion identified using CT. Histopathologic evaluation of the nasal mass was consistent with a ganglioneuroma. The dog was treated with 10 × 4.2 Gy using IMRT technique. Post radiation therapy (RT), improvement in clinical signs were noted. Tumor progressed in size based on CT evaluation at 49 days, 3, and 6 months post-treatment. A grade 2 oral mucositis was the only RT side effect noted. Radiation therapy as described above was completed without evidence of high-grade radiation toxicities and has potential to improve clinical signs but failed to induce tumor response.

Neoplastic melanocytic pleural effusion in a Portuguese water dog.

A 9-year-old castrated male Portuguese water dog was presented following incomplete excision of a malignant melanoma at the left lip commissure by the referring veterinarian. Physical examination was otherwise unremarkable. The patient was staged using thoracic radiographs, abdominal ultrasound, and fine-needle aspirates of the mandibular lymph nodes and spleen. Given the absence of any definitive evidence of metastasis, the malignant melanoma was surgically completely removed. The dog then received four melanoma vaccine doses as an adjuvant therapy and remained clinically healthy for more than 3 months after the last immunization. However, 232 days after the initial discovery of the lip mass, the dog was euthanized due to deterioration and a poor prognosis based on the presence of lung metastases and neoplastic melanocytic pleural effusion. The latter has been rarely reported in dogs, despite the high prevalence of oral malignant melanomas and the tendency of these tumors to metastasize to the lungs.

Tonsillar plasmacytoma in a dog.

A 10-year-old greyhound dog was presented because of an incidental finding of a tonsillar mass. Excisional surgical biopsy was performed and the dog was diagnosed with an incompletely resected plasma cell tumor. Adjuvant therapy was declined. One year later there was no local recurrence or distant metastasis of the mass or clinical signs associated with the tonsillar plasmacytoma.

Plasmacytome tonsillaire chez un chien. Un chien Greyhound âgé de 10 ans a été présenté en raison de la découverte fortuite d'une masse tonsillaire. Une biopsie par excision chirurgicale a été réalisée et le chien a été diagnostiqué avec une tumeur à plasmocytes avec résection incomplète. Le traitement avec adjuvant a été refusé. Une année plus tard, il n'y avait aucune récurrence locale ou de métastase distante de la masse ou de signes cliniques associés au plasmacytome tonsillaire.(Traduit par Isabelle Vallières).

A novel canine histiocytic sarcoma cell line: initial characterization and utilization for drug screening studies.

BACKGROUND: Histiocytic sarcoma is a rare disorder in humans, however it is seen with appreciable frequency in certain breeds of dogs, such as Bernese mountain dog. The purpose of this study was to fully characterize a novel canine histiocytic sarcoma cell line, and utilize it as a tool to screen for potential therapeutic drugs. METHODS: The histiocytic sarcoma cell line was characterized by expression of cellular markers as determined by immunohistochemistry and flow cytometry techniques. The neoplastic cells were also evaluated for their capability of phagocytizing beads particles, and their potential to grow as xenograft in an immunodeficient mouse. We investigated the in vitro cytotoxic activity of a panel of thirteen compounds using the MTS proliferation assay. Inhibitory effects of different drugs were compared using one-way ANOVA, and multiple means were compared using Tukey's test. RESULTS: Neoplastic cells expressed CD11c, CD14, CD18, CD45, CD172a, CD204, MHC I, and vimentin. Expression of MHC II was upregulated after exposure to LPS. Furthermore, the established cell line clearly demonstrated phagocytic activity similar to positive controls of macrophage cell line. The xenograft mouse developed a palpable subcutaneous soft tissue mass after 29 days of inoculation, which histologically resembled the primary neoplasm. Dasatinib, a tyrosine kinase pan-inhibitor, significantly inhibited the growth of the cells in vitro within a clinically achievable and tolerable plasma concentration. The inhibitory response to dasatinib was augmented when combined with doxorubicin. CONCLUSIONS: In the present study we demonstrated that a novel canine histiocytic sarcoma cell line presents a valuable tool to evaluate novel treatment approaches. The neoplastic cell line favorably responded to dasatinib, which represents a promising anticancer strategy for the treatment of this malignancy in dogs and similar disorders in humans.

Prostate cancer characterization by optical contrast enhanced photoacoustics.

During the past decades, prostate cancer (PCa), with an annual incident rate much higher than any other cancer, is the most commonly diagnosed cancer in American men. PCa has a relatively low progression rate yet the survival percentage decreases dramatically once the cancer has metastasized. Identifying aggressive from indolent PCa to prevent metastasis and death is critical to improve outcomes for patients with PCa. Standard procedure for assessing the aggressiveness of PCa involves the removal of tumor tissues by transrectal (TR) ultrasound (US) guided needle biopsy. The microscopic architecture of the biopsied tissue is visualized by histological or immunohistochemical staining procedures. The heterogeneity of the microscopic architecture is characterized by a Gleason score, a quantitative description of the aggressiveness of PCa. Due to the inability to identify the cancer cells, most noninvasive imaging modalities can only provide diagnosis of PCa at limited accuracy. This study investigates the feasibility of identifying PCa tumors and characterizing the aggressiveness of PCa by photoacoustic imaging assisted by cancer targeting polyacrylamide (PAA) nanoparticles (NPs). PAA is a biocompatible material used in clinics for the past 20 years. PAA NPs can protect capsulated optical contrast agents from interference by enzymes and enable prolonged systematic circulation in the living biological environment. The cancer targeting mechanism is achieved by conjugating the NPs to F3 peptides, which trace nucleolin overexpressed on the surface of cancer cells. Preliminary studies have shown that the NPs are capable of staining the PCa cells in vivo.

Clinical, morphological, and molecular characterization of Penicillium canis sp. nov., isolated from a dog with osteomyelitis.

Infections caused by Penicillium species are rare in dogs, and the prognosis in these cases is poor. An unknown species of Penicillium was isolated from a bone lesion in a young dog with osteomyelitis of the right ilium. Extensive diagnostic evaluation did not reveal evidence of dissemination. Resolution of lameness and clinical stability of disease were achieved with intravenous phospholipid-complexed amphotericin B initially, followed by long-term combination therapy with terbinafine and ketoconazole. A detailed morphological and molecular characterization of the mold was undertaken. Sequence analysis of the internal transcribed spacer revealed the isolate to be closely related to Penicillium menonorum and Penicillium pimiteouiense. Additional sequence analysis of ß-tubulin, calmodulin, minichromosome maintenance factor, DNA-dependent RNA polymerase, and pre-rRNA processing protein revealed the isolate to be a novel species; the name Penicillium canis sp. nov. is proposed. Morphologically, smooth, ovoid conidia, a greenish gray colony color, slow growth on all media, and a failure to form ascomata distinguish this species from closely related Penicillium species.

Hemostatic abnormalities in dogs with carcinoma: a thromboelastographic characterization of hypercoagulability.

Hemostatic abnormalities were investigated in 32 dogs with carcinoma and 19 age-matched healthy dogs. Thromboelastography, hemostasis profile (i.e. prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen concentration), platelet count (PLT), thrombin-antithrombin complexes (TAT), and plasminogen activator inhibitor-1 (PAI-1) activity were evaluated. Dogs with carcinomas had faster thrombus generation (TEG(TG), a mathematic value obtained from the first derivate of the thromboelastographic tracing; 834.8±91.1 vs. 707.8±75.8mm/min; mean±SD), increased fibrinogen concentration (276 vs. 151mg/dL), and PLT (425 vs. 324U×10(9)/L), but had decreased PAI-1 activity (15.7 vs. 26.2IU/mL).The most common hemostatic abnormalities found in carcinoma dogs were hypercoagulability (TEG(TG)>mean+2 SD of healthy dogs) and thrombocytosis (PLT>424×10(9)U/L) in 46% of cases, and hyperfibrinogenemia (fibrinogen >384mg/dL) in 32% of cases. Disseminated intravascular coagulation was uncommon and the extent of disease was not correlated with hypercoagulability. TEG(TG) showed good correlation with fibrinogen (r=0.80) and hyperfibrinogenemia seems to be a main factor of the hypercoagulable state in carcinoma dogs. In conclusion, TEG(TG) is a valid parameter to diagnose hypercoagulability.

Thromboelastography in healthy horses and horses with inflammatory gastrointestinal disorders and suspected coagulopathies.

OBJECTIVES: To evaluate the use of citrated recalcified (nonactivated) thromboelastography (TEG) in healthy horses and horses with colitis and suspected coagulopathies. DESIGN: Prospective, observational study conducted between October 2007 and June 2009. SETTING: Veterinary Teaching Hospital. ANIMALS: Forty-five healthy adult horses and 12 sick adult horses with colitis and prolonged prothrombin time (PT) or activated partial thromboplastin time (aPTT). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Whole blood was collected on admission. Coagulation profile (PT, aPTT, platelet count, and fibrinogen concentration) and citrated recalcified whole blood TEG analysis (R-time [R], K-time [K], angle [α], maximum amplitude [MA], G value [G], lysis at 60 min [LY60]) were evaluated. Mean values (SD) for TEG parameters in healthy horses were: R=10.4 (3.1) minutes; K=3.5 (1.2) minutes; α=46.3 (11.0)°; MA=55.6 (5.1) mm; G=6,429 (1,341) dyn/cm², and LY60=5.1 (2.4)%. Mean coefficients of variation for intra-assay/interindividual variability in healthy horses were: R=4.7%/30.7%, K=4.8%/35.3%, α=4.4%/23.8%, MA=1.4%/9.3%, G=3.4%/20.8%, and LY60=13.1%/47.7%, respectively. Horses with colitis and prolonged PT and/or aPTT had longer mean values for R (P<0.001) and K (P<0.001), narrower mean α (P<0.001), decreased mean MA (P=0.001), and smaller mean G (P=0.02); changes consistent with hypocoagulability. CONCLUSIONS: Citrated recalcified (nonactivated) TEG demonstrated changes consistent with hypocoagulability in horses with colitis that had preidentified coagulation abnormalities. This technique has high interindividual variability and low intra-assay variability. TEG may be useful for detecting hypocoagulable states in horses with colitis and suspected coagulopathies.