Megakaryocyte myelosis in cats: review and case report

Disseminated megakaryocytic neoplasia was diagnosed in a 3-year-old cat. Hepatomegaly, splenomegaly, and abnormal platelets in the peripheral blood characterized the condition. Neoplastic megakaryocytes were present in numerous organs. No evidence of feline leukemia virus was found.     

Fibrotic Myopathy of the Semitendinosus Muscle in Four Dogs

Fibrosis of the semitendinosus muscle resulted in a characteristic gait abnormality in four male German shepherd dogs. Blood chemistry, electrophoresis, and electromyographic studies were performed. Surgery was undertaken in each case to relieve the restricting fibrous tissue. The lameness returned with reappearance of the fibrous band within six months. The etiology of fibrotic myopathy is unknown, but electromyographic studies and electrophoresis results suggest a myopathy due to chronic inflammation. Histopathologic exam reveals replacement of degenerating muscle fibers with connective tissue.     

A Comparison of Surgical Training with Live Anesthetized Dogs and Cadavers

Cadavers were compared with live anesthetized dogs for their effectiveness as models for surgical training of veterinary medical students. One group of students was trained using cadavers, and a peer group was trained using live anesthetized dogs. Both groups then performed an intestinal anastomosis using a live subject. The time to completion of the procedure was recorded. The anastomoses and celiotomy closures were evaluated. Each anastomosis was isolated and pressure tested. Reviewers blindly scored each surgical team's performance based on actual inspection of the surgical site and on viewing videotapes of the procedure. The participants' attitudes toward the use of live animals in teaching and research were documented before and after training. No statistically significant differences could be detected between the two groups. The results suggest that some substitution of cadavers for live dogs in surgical training might be feasible.     

USE OF 3'-DEOXY-3'-[18F]FLUOROTHYMIDINE PET/CT FOR EVALUATING RESPONSE TO CYTOTOXIC CHEMOTHERAPY IN DOGS WITH NON-HODGKIN'S LYMPHOMA

Imaging and measurement of proliferation with computed tomography (CT) and positron emission tomography (PET) provide a noninvasive method for improved staging and monitoring of response to cancer treatment. We evaluated prospectively the proliferation marker 3'-deoxy-3'[¹⁸F] fluorothymidine (FLT) in the context of FLT-PET/CT for detection of early response, confirmation of posttreatment response, and prediction of relapse in dogs with non-Hodgkin's lymphoma. Nine dogs with non-Hodgkin's lymphoma who were scheduled to receive five cycles of an investigational cytotoxic chemotherapy agent were included. All dogs received baseline FLT-PET/CT imaging immediately before chemotherapy. Intent was to repeat imaging with FLT-PET/CT at various time points: group 1 ( n =4), 5 days after initiation of chemotherapy and 3 weeks following the last chemotherapy administration; group 2 ( n =5), before the fourth cycle of chemotherapy and 3 weeks following the last administration. Two dogs in group 2 did not undergo repeat PET/CT. Body mass standardized uptake values (SUV) for FLT were calculated for each dog. Eight dogs had initially increased FLT uptake (mean SUV_max=9.8 [2.6–22.3]). Mean SUV decreased significantly for the seven dogs that underwent follow-up PET/CT following chemotherapy (mean SUV_max=3.5 [1.1–7.9], P <0.016). Increased uptake preceded clinical and cytological evidence of relapse in two dogs. Ki-67 immunohistochemistry confirmed decreased proliferation corresponding to decreased SUV in three canine lymph node samples. FLT-PET/CT functional and anatomical imaging shows promise for the evaluation of response to cytotoxic chemotherapy in dogs with non-Hodgkin's lymphoma and for predicting relapse before standard clinical and clinicopathologic confirmation.     

Chlorophyll production and chloroplast development in norflurazon-treated plants

The chlorophyll production of wheat (Triticum vulgare L. cv. Mericopa), corn (Zea mays L. cv. Everta), and alfalfa (Medicago sativa L. cv. Saranac), treated with the herbicide 4-chloro-5-methylamino-2-(3-trifluoro-methylphenyl)pyridazin- 3-one (norflurazon) and grown under high light intensity (10 760 lux) was markedly reduced. Corn and wheat seedlings germinated and grown for 7 days in an agar medium containing 1 mg/1 norflurazon were almost completely bleached. Alfalfa was even more sensitive to norflurazon, 0.1 mg/1 causing almost complete chlorosis. Under low light intensity (10.76 lux) the influence of norflurazon on chlorophyll production was greatly reduced. It is thought that norflurazon inhibits carotenoid synthesis leaving the chlorophyll of the plant subject to photooxidation. Electron micrographs of chloroplasts from green, partially bleached, and bleached areas of corn leaves treated with norflurazon indicate that the herbicide causes progressive deterioration of the lamellar system.