Biomedical subjects
Publications and source records attributed to C B Grindem.
Transmission and scanning electron microscopic characteristics of leukemic cells from eight cats with spontaneous leukemia are described. Nuclear blebs, myelin figures, cytoplasmic microfibrils and C-type virus were seen more frequently in leukemic cells. Surface ridges and ruffles seen with the scanning electron microscopy were helpful in distinguishing myelogenous from lymphogenous leukemia.
Transmission and/or scanning electron microscopic features of leukemic cells from seven dogs with myelomonocytic leukemia, four dogs with monocytic leukemia, and three dogs with lymphocytic leukemia were studied. Few ultrastructural features distinguished normal cells from leukemic cells. Nuclear to cytoplasmic asynchrony, abnormal cytoplasmic granules, nuclear pockets, and cytoplasmic fibrillar bundles were seen more frequently in leukemic cells. Small ridges or ruffles and a few microvilli were surface characteristics of cells from dogs with myelomonocytic leukemia. An occasional cell had large undulating ruffles. Cells from dogs with monocytic leukemia and lymphocytic leukemia usually had smoother surfaces.
Concurrent systemic lupus erythematosus (SLE) and amyloidosis (renal and splenic) are reported in a 7-year-old female miniature Schnauzer. Treatment of tissue sections with potassium permanganate and dilute sulphuric acid prior to staining with Congo red indicated that the amyloid in this case is composed of AA protein (i.e. reactive systemic amyloid or so-called secondary amyloid). The rare association of amyloidosis and SLE, in both man and the dog, and the association with granulomatous pneumonia and leukopenia in this case are discussed.
An analysis was made of 17 cases of microscopically proven rib neoplasms, with the objective of evaluating the variability of clinical and radiographic findings, the neoplastic cell types, the occurrence of metastases, and the survival time following the diagnosis. In 15 dogs with primary rib neoplasms and in 2 dogs with secondary (presumably metastatic) rib neoplasms, the clinical signs commonly included dyspnea and a localized swelling on the thoracic wall. For the dogs with primary rib neoplasms, the mean age was 4.5 years, with a range of 1.3 to 16 years. On radiography, rib osteolysis, extra and/or intrathoracic soft tissue masses often containing areas of mineralization, and pleural effusion were commonly identified. Ribs 5 through 9 were the most commonly affected and the right side was involved twice as often as the left side. Osteosarcoma was the most frequently diagnosed tumor, but chondrosarcomas and hemangiosarcoma were also found. At necropsy, over 50% of the dogs with primary rib neoplasms had metastases in the lungs. Less than 10% of the dogs with primary rib osteosarcomas survived more than 4 months after the diagnosis.
Cutaneous lymphoma (mycosis fungoides) was diagnosed by multiple biopsies of nonulcerated cutaneous lesions in 13 dogs. The disease was initially characterized by erythema and alopecia of the trunk. Subsequently severe scaling, pruritus, and skin nodules developed. Lymph nodes were usually normal in size during early stages of the disease but became enlarged as the disease became extensive. Four dogs were treated with cytotoxic drugs. Marked improvement of skin lesions occurred in 3 dogs, but treatment did not prevent development of extra-cutaneous lesions.
Ten student surgery ponies were subjected to exploratory laparotomy. Abdominal paracentesis was performed preoperatively and daily postoperatively for 6 days, then the ponies were euthanatized and necropsied. Initial baseline peritoneal fluid parameters were within established reference limits. Postoperatively, the total leukocyte count and total protein in the peritoneal fluid rose and remained elevated for the 6 days of the study. Complete blood counts (CBCs) were performed preoperatively and on days 1 and 4 postoperatively. On day 1, a stress leukogram with a mild inflammatory component developed, but by day 4, the CBCs were within normal limits. The mean plasma fibrinogen levels, which were determined daily, peaked on day 4.
The prevalence of feline thrombocytopenia (< 200,000 platelets/microL) at North Carolina State University, College of Veterinary Medicine Teaching Hospital, from January 1985 to March 1990, was 1.2% (41/3300). Cats were divided into six categories based on clinical diagnoses: 29% (12/41) had infectious disease, 20% (8/41) had neoplasia, 7% (3/41) had cardiac disease, 2% (1/41) had primary immune-mediated disease, 22% (9/41) had multiple diseases, and 20% (8/41) had disorders of unknown etiology. The mean platelet count for all thrombocytopenic cats was 52,000/microL +/- 46,000/microL (1 SD) with a range of 1000-190,000/microL. No significant differences were found between groups with respect to platelet count, packed cell volume, or white blood cell count, though anemia and leukopenia were common among the cats as a whole. Bleeding disorders (hemorrhage or thrombosis) were observed in 29% (12/41) of thrombocytopenic cats and were more likely to be associated with neoplasia, cardiac disease, and platelet counts less than or equal to 30,000/microL. Disseminated intravascular coagulopathy was diagnosed in 12% (5/41) of the cats. Infections and/or neoplasia affecting the bone marrow were the most common diseases associated with thrombocytopenia. Feline leukemia virus and myeloproliferative neoplasia accounted for approximately 44% (18/41) of the specific diagnoses in thrombocytopenic cats.
Ten percent (214/2,059) of all dogs with cancer at North Carolina State University Veterinary Teaching Hospital had thrombocytopenia. The thrombocytopenia was associated with infectious/inflammatory etiologies in 4%, miscellaneous disorders (therapy, bone marrow failure, disseminated intravascular coagulation) in 35%, and neoplasia without identifiable secondary factors in 61% of cancer-bearing dogs. Classifying these dogs by tumor groups revealed the following proportionate ratios: lymphoid, 29%; carcinoma, 28%; sarcoma, 20%; hemic neoplasia, 7%; multiple, 5%; unclassified, 3%; benign, 3%; brain, 3%; and endocrine, 3%. Dogs with hemangiosarcoma, lymphoma, and melanoma were at increased risk of developing thrombocytopenia. Cytotoxic therapy was the major factor increasing the risk of thrombocytopenia in dogs with melanoma. Golden Retrievers were the only breed recognized with a predisposition to develop thrombocytopenia. If thrombocytopenia is identified in a dog with cancer, we recommend thorough evaluation of the coagulation system before surgery or therapy, and careful consideration of the risks and potential benefits of myelosuppressive or L-asparaginase therapy.
Medical records of 3 dogs from North Carolina and 3 dogs from Virginia with ehrlichial morulae in circulating neutrophils were studied retrospectively. Two clinically distinct disease syndromes, including chronic, moderate to severe anemia (n = 3) and polyarthritis (n = 2) were associated with canine granulocytic ehrlichiosis (CGE) in these dogs. One dog was clinically healthy, and abnormalities were not detected during physical examination. Clinical signs were nonspecific and included fever, lethargy, anorexia, vomiting, and diarrhea. The most frequent laboratory abnormalities were normocytic normochromic nonregenerative anemia, moderate thrombocytopenia with large platelets, lymphopenia, and eosinopenia. Considerable variability was found in the serologic responses to Ehrlichia equi, Ehrlichia canis, and Ehrlichia chaffeensis antigens among the 5 dogs for which stored sera were available for indirect fluorescent antibody testing. Polymerase chain reaction amplification and sequencing of portions of the 16S rRNA gene from blood (collected in ethylenediaminetetraacetic acid) of 1 severely anemic dog (dog 3) and 1 polyarthritic dog (dog 4) resulted in DNA sequences nearly identical to the GenBank accessions for Ehrlichia ewingii. The DNA sequence from a 3rd dog (dog 5) was most similar to that of E. canis. Serologic or molecular results support the possibility of E. ewingii, E. equi, and E. canis coinfection or serologic cross-reactivity among canine granulocytic and monocytic Ehrlichia species in dogs from North Carolina and Virginia. Variability in response to tetracycline or doxycycline treatment was noted in these dogs, with more rapid resolution of signs in dogs with polyarthritis. We report the 1st cases of CGE in dogs from North Carolina and Virginia, including recognition of CGE in a healthy dog.
Antiplatelet antibodies were detected in the sera of dogs with naturally occurring and experimentally induced Rickettsia rickettsii and Ehrlichia canis infections. This is the first known report documenting elevated platelet-associated immunoglobulin (PAIg) titers in Rocky Mountain spotted fever (RMSF) infections. In the naturally occurring RMSF infections and ehrlichiosis, the antibodies persisted for weeks or months, even when the platelet counts had normalized. Results of this study indicate an immunological component for rickettsial thrombocytopenia. Therefore, current therapeutic recommendations, especially regarding avoiding the use of immunosuppressive drugs in patients with rickettsial diseases, need to be critically reviewed.
One hundred ninety six dogs with spontaneously occurring lymphoproliferative disorders were immunophenotyped. Dogs with lymphoma (175) were determined to be derived from B-cells in 134/175 (76%), T-cells in 38/175 (22%) and 3/175 (2%) were null cells (non-reactive with any canine-specific lymphocyte antibody). Dogs with T-cell lymphomas were at significantly higher risk of relapse and early death compared with B-cell lineage lymphoma following therapy (52 vs. 160 days; p < 0.001 and 153 vs. 330 days; p < 0.001, respectively). Hypercalcemia was associated only with CD4+ lymphomas. A nonimmunoglobulin B-cell marker (B5), expressed in 95% of nonneoplastic lymphocytes, was expressed at a reduced level in 63% (64/104) of dogs with B-cell lymphoma. Dogs with lymphoma in which the B5 antigen was expressed below normal levels experienced shorter progression free survival (125 vs. 202 days; p < 0.05) and overall survival times (203 vs. 385 days; p < 0.05) than dogs with B-cell lymphoma in which the B5 antigen was expressed normally. Chronic lymphocytic leukemia in dogs was primarily associated with a CD8+ phenotype (8/12) and acute lymphoblastic leukemia was determined to be of either null cell (4/9) or T-cell (3/9) phenotype. Although canine and human non-Hodgkin's lymphoma are phenotypically similar, canine leukemia is phenotypically distinct from human leukemia. The development of canine-specific probes has facilitated a priori assessment of treatment outcome in dogs with lymphoma and may in the future contribute to the comparative understanding of leukemo- and lymphoma-genesis in these species.