Lomustine (CCNU) and prednisone chemotherapy for high-grade completely excised canine mast cell tumors.

The efficacy and toxicity of lomustine and prednisone for treating high-grade completely excised mast cell tumors (MCTs) was evaluated in a retrospective study of 15 dogs. Dogs were treated with lomustine (CCNU) at 70 mg/m2 every 4 weeks and prednisone at 0.5 to 1 mg/kg body weight PO daily. Eight dogs had treatment failures due to recurrence at the site of the initial surgery (2/15), de novo cutaneous MCT (4/15), or metastatic disease (2/15). The median overall survival time was 904 days, with 9 dogs alive at 1 year and 6 dogs alive after 2 years. All but 2 of the dogs had toxicity throughout their treatment protocol, with neutropenia (67%) and elevations in ALT (60%) being the most common; however, no dogs required hospitalization. The protocol was overall well-tolerated and lomustine/prednisone should be considered in the adjunctive treatment of high-grade mast cell tumors.

Chimiothérapie avec lomustine (CCNU) et prednisone pour le traitement de tumeurs mastocytaires de grade élevé complètement excisées. L'efficacité et la toxicité de la lomustine et de la prednisone pour traiter des tumeurs mastocytaires (MCTs) de grade élevé complètement excisées furent évaluées dans une étude rétrospective de 15 chiens. Les chiens furent traités avec la lomustine (CCNU) à un dosage de 70 mg/m2 aux 4 semaines et avec de la prednisone à un dosage de 0,5 à 1 mg/kg de poids corporel PO quotidiennement. Un échec de traitement est survenu chez huit chiens étant donné la récurrence au site de la chirurgie initiale (2/15), une MCT cutanée de novo (4/15), ou une maladie métastasique (2/15). Globalement, la médiane du temps de survie était de 904 jours, avec neuf chiens toujours vivants après 1 an et 6 chiens toujours vivants après 2 ans. À l'exception de deux chiens, tous les chiens présentèrent des signes de toxicité durant toute la durée de leur protocole de traitement, la neutropénie (67 %) et une augmentation de l'ALT (60 %) étant les plus communes; toutefois, aucun chien ne nécessita d'être hospitalisé. Le protocole était généralement bien toléré et la combinaison lomustine/prednisone devrait être considérée dans le traitement complémentaire des tumeurs mastocytaires de grade élevé.(Traduit par Dr Serge Messier).

Evaluation of lymph node aspirates at diagnosis and relapse in dogs with high-grade multicentric lymphoma and comparison with survival time.

BACKGROUND: Canine high-grade multicentric lymphoma, a common disease with variable response to chemotherapy, is often diagnosed using cytology. OBJECTIVES: The purpose of the study was to compare cytologic features of canine peripheral lymph node aspirates collected at diagnosis and at relapse, and evaluate their usefulness in predicting survival. METHODS: Cytologic scoring based on a rubric and nuclear morphometry analyses were performed on cytologic smears collected at diagnosis and at relapse. Scores at diagnosis and relapse were compared by paired t-test and evaluated in relation to time from diagnosis to remission, remission to relapse, relapse to death, and total survival time, using the Cox proportional-hazards regression model. RESULTS: Number of mitoses and total cytologic score were significantly higher at relapse compared to diagnosis (P < .05). None of the nuclear morphometry measures were significantly different between diagnosis and relapse. The presence of binucleated or multinucleated cells at diagnosis was associated with a shorter remission and decreased total survival (P < .05). Increased mean nucleoli at relapse was associated with longer remission and total survival (P < .05). Increased minimum nuclear radius and diameter at diagnosis were associated with a decreased time from relapse to death (P < .05). Several nuclear morphometry measures at relapse were associated with a shorter time from diagnosis to remission (P < .05). CONCLUSIONS: Number of mitoses and total score were higher at relapse than at diagnosis in canine lymphoma. The presence of binucleated or multinucleated cells at diagnosis may be useful as indicator of a poor prognosis. Further studies including a larger number of cases are required to reinforce the prognostic values of these cytologic features.

Yeast eIF4B binds to the head of the 40S ribosomal subunit and promotes mRNA recruitment through its N-terminal and internal repeat domains.

Eukaryotic translation initiation factor (eIF)4B stimulates recruitment of mRNA to the 43S ribosomal pre-initiation complex (PIC). Yeast eIF4B (yeIF4B), shown previously to bind single-stranded (ss) RNA, consists of an N-terminal domain (NTD), predicted to be unstructured in solution; an RNA-recognition motif (RRM); an unusual domain comprised of seven imperfect repeats of 26 amino acids; and a C-terminal domain. Although the mechanism of yeIF4B action has remained obscure, most models have suggested central roles for its RRM and ssRNA-binding activity. We have dissected the functions of yeIF4B's domains and show that the RRM and its ssRNA-binding activity are dispensable in vitro and in vivo. Instead, our data indicate that the 7-repeats and NTD are the most critical domains, which mediate binding of yeIF4B to the head of the 40S ribosomal subunit via interaction with Rps20. This interaction induces structural changes in the ribosome's mRNA entry channel that could facilitate mRNA loading. We also show that yeIF4B strongly promotes productive interaction of eIF4A with the 43S•mRNA PIC in a manner required for efficient mRNA recruitment.

What is your diagnosis? Ventral neck mass in a dog.

: A 14-year-old male Labrador Retriever was presented for lethargy and collapse. On physical examination, numerous abnormalities were found, including a large ventral neck mass (100 cm(3)) in the area of the thyroid gland. Fine-needle aspirates revealed 2 apparent populations of cells: one suspected to be a well-differentiated thyroid carcinoma, and the other consisting of large pleomorphic to spindloid cells suggestive of sarcoma. Two days later, the dog died at home. A full necropsy was not performed, but examination of the head and neck revealed a well-encapsulated mass adjacent to the cranial trachea and larynx. A section of the mass was evaluated histologically and a diagnosis of anaplastic thyroid carcinoma was made. Immunohistochemical evaluation with antibodies to thyroglobulin, cytokeratin, and vimentin confirmed distinct populations of malignant epithelial and malignant mesenchymal cells, and the diagnosis was amended to thyroid carcinosarcoma. Thyroid carcinosarcoma is a rare neoplasm in dogs in which the cell type comprising the mesenchymal component can vary. Immunochemistry to demonstrate the 2 cell types may be necessary to differentiate thyroid carcinosarcoma from anaplastic thyroid carcinoma.

Clinical signs, treatments, and outcome in cats with transitional cell carcinoma of the urinary bladder: 20 cases (1990-2004).

OBJECTIVE: To characterize demographics and clinical signs and evaluate outcomes of treatments in cats with transitional cell carcinoma (TCC) of the urinary bladder. DESIGN: Retrospective case series. ANIMALS: 20 cats with TCC. PROCEDURES: Medical records of 20 cats with a bladder mass identified as a TCC that were examined at 2 veterinary institutions between 1990 and 2004 were evaluated. Signalment, treatments, and outcome were assessed. RESULTS: Breeds included domestic short hair (n=14), long hair (2), and medium hair (2) cats, Siamese (1), and Abyssinian (1). All cats had been neutered at an early age (< 1 year old; 13 neutered males and 7 spayed females). The median age at diagnosis of TCC was 15.2 years. The trigone region was affected in 9 cats. Treatments included piroxicam administration, chemotherapy, or surgery as single interventions or in combination; 6 cats were not treated. At the time of diagnosis, 3 cats had pulmonary metastasis and 1 cat had metastasis to local lymph nodes. Median survival time for all 20 cats was 261 days. Nearly all deaths were attributable to progressive disease in the urinary tract. Five cats were lost to follow-up. CONCLUSIONS AND CLINICAL RELEVANCE: In cats, TCC of the urinary bladder appears to be a rare and aggressive disease that is more prevalent in male cats and frequently develops at sites distant from the trigone (unlike TCC in dogs). Nevertheless, initial clinical signs of TCC in cats in this study were similar to those reported for affected dogs.