PubMed Health⌕ Search

Biomedical subjects

E A Mahaffey

Publications and source records attributed to E A Mahaffey.

At least 19 recordsLinked to original sources

Evaluation of an in-house centrifugal hematology analyzer for use in veterinary practice.

OBJECTIVE: To compare CBC results obtained by use of an in-house centrifugal analyzer with results of a reference method. DESIGN: Prospective study. SAMPLE POPULATION: Blood samples from 147 dogs, 42 cats, and 60 horses admitted to a veterinary teaching hospital and from 24 cows in a commercial dairy herd. PROCEDURE: Results obtained with the centrifugal analyzer were compared with results obtained with an electrical-impedance light-scatter hematology analyzer and manual differential cell counting (reference method). RESULTS: The centrifugal analyzer yielded error messages for 50 of 273 (18%) samples. Error messages were most common for samples with values outside established reference ranges. Correlation coefficients ranged from 0.80 to 0.99 for Hct, 0.55 to 0.90 for platelet count, 0.76 to 0.95 for total WBC count, and 0.63 (cattle) to 0.82 (cats) to 0.95 (dogs and horses) for granulocyte count. Coefficients for mononuclear cell (combined lymphocyte and monocyte) counts were 0.56, 0.65, 0.68, and 0.92 for cats, horses, dogs, and cattle, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that there was an excellent correlation between results of the centrifugal analyzer and results of the reference method only for Hct in feline, canine, and equine samples; WBC count in canine and equine samples; granulocyte count in canine and equine samples; and reticulocyte count in canine samples. However, an inability to identify abnormal cells, the high percentage of error messages, particularly for samples with abnormal WBC counts, and the wide confidence intervals precluded reliance on differential cell counts obtained with the centrifugal analyzer.

Animals↗

Extramedullary plasmacytoma in the trachea of a dog.

A 10-year-old spayed female mixed-breed dog was examined because of acute inspiratory dyspnea. Radiography and tracheoscopy revealed a discrete, solitary mass originating from the membranous portion of the trachea at the level of the thoracic inlet. Tracheal resection and anastomosis were performed, and on histologic examination of the resected tissue, extramedullary plasmacytoma was diagnosed. Although tracheal tumors are rare in dogs, they should be considered during evaluation of dogs with signs of airway obstruction. Prognosis is excellent for dogs with extramedullary plasmacytoma in which surgical excision is complete.

Anastomosis, Surgical↗

Equine malignant lymphomas: morphologic and immunohistochemical classification.

Gross lesions, microscopic appearance, and immunophenotyping are reported in a retrospective study of 31 cases of equine malignant lymphoma. Immunohistochemical studies were performed on archived formalin-fixed, paraffin-embedded tissues. Monoclonal antibodies to surface glycoprotein BLA.36 and intracytoplasmic domains of mb-1 and B29 were used to document the presence of B lymphocytes in the equine tumors. Polyclonal antibody to CD3 and monoclonal antibodies to T-lymphocyte markers CD3 and CD5 revealed the presence of variable numbers of T cells within the equine lymphomas. The neoplastic component of the equine lymphomas was determined through morphologic evaluation, immunophenotyping, and the use of proliferation markers Ki-67 and proliferating cell nuclear antigen. Equine malignant lymphomas were composed of a heterogeneous cell population. Most tumors contained B and T lymphocytes. Twenty-four horses had diffuse lymphomas derived from B lymphocytes. Thirteen of these lymphomas contained primarily neoplastic B lymphocytes. Eleven additional cases of diffuse large B-cell lymphoma contained from 40% to 80% nonneoplastic T lymphocytes and were classified as T-cell-rich, large B-cell lymphomas. This is the first description of T-cell-rich, B-cell lymphoma in the horse. Six tumors with a diffuse architecture were derived from T lymphocytes. Four T-cell tumors were large-cell tumors, 1 was a small-cell tumor, and in 1 tumor the size of the cells could not be determined accurately because of autolytic change in the tissues. One diffuse large-cell lymphoma did not react with either B- or T-cell markers.

Animals↗

Surgical treatment of a septic dentigerous cyst in a goat.

A slowly growing lesion of the rostral mandible of a goat was diagnosed to be a septic dentigerous cyst. The lesion was treated surgically to remove one displaced tooth and debride the cystic cavity, and systemic antibiotic therapy was applied. Thirty-four weeks later the goat was clinically and radiographically improved and the problem had not recurred.

Animals↗

Detection of equine and bovine T- and B-lymphocytes in formalin-fixed paraffin-embedded tissues.

Formalin-fixed paraffin-embedded sections of equine and bovine lymph nodes, spleen, thymus, and Peyer's patches were incubated with monoclonal antibodies to B-lymphocyte markers BLA.36, B29, and mb-1 and T-lymphocyte markers CD3 and CD5. The monoclonal antibody BLA.36 reacted with 80-90% of lymphocytes in the germinal centers and mantle zones of follicles in lymph nodes, spleen, and Peyer's patches. In addition, 90% of lymphocytes in the marginal zone of the spleen, and variable numbers of lymphocytes within lymph node medullary cords were immunopositive for BLA.36. Antibodies to B29 and mb-1 produced similar staining patterns as BLA.36 with fewer positive cells in the germinal centers and medullary cords. BLA.36, B29, and mb-1 reacted with 30-50% of lymphocytes in the medulla of the thymus and with 5-10% of lymphocytes in the cortex. CD3 and CD5 reacted with 90% of lymphocytes in the paracortex and parafollicular zones of lymph nodes, spleen, and Peyer's patches; 40-50% of lymphocytes in the medullary cords of lymph nodes, and scattered positive cells within follicles. Anti-CD3 antibody reacted with 95% of lymphocytes in the splenic red pulp, but antibodies directed against CD5 reacted only faintly with approximately 5-10% of lymphocytes in the red pulp. CD3 and CD5 reacted with 50-60% of cells in the medulla of the thymus and with 40-80% of lymphocytes in the thymic cortex. The biochemical characterization of the antibodies by Western blotting against lysates of equine and bovine peripheral blood mononuclear cells confirmed that antibodies to BLA.36, mb-1, B29, CD3, and CD5 detected molecules of the same approximate molecular mass as found on lymphoid cells of human beings and rats.

Animals↗

Accuracy of interpretation of microscopic images of cytologic, hematologic, and histologic specimens using a low-resolution desktop video conferencing system.

OBJECTIVE: To determine the accuracy of interpretation of microscopic images for pathologic study transmitted over Switched-56 lines using a desktop interactive video conferencing system. MATERIALS AND METHODS: In subjective studies, two systems were connected using null-modem cables, which allowed evaluation of different bandwidths from 56 kbps to 384 kbps. Objective studies were done with two systems connected at distant sites via paired Switched-56 lines that produced an effective bandwidth of 112 kbps. A video camera mounted on a microscope was attached to the sending system. The resolution of the video image on the video conferencing system was 352 x 288 lines. Cases for cytology, hematology, and histopathology studies were selected from archives; one pathologist transmitted microscopic images, and a second pathologist made interpretations. The three pathologists were Board certified with similar experience that ranged from 20 to 35 years. Categories of interpretations or observations were predetermined for each study to allow the data on agreement between the direct microscopic interpretation or observation and that recorded by the receiving pathologist to be corrected for agreement attributable to chance alone. The results were analyzed using the kappa statistic. RESULTS: In the subjective studies, image degradation prevented interpretation while the microscope stage was moved. This problem occurred at all bandwidths tested. Image quality limited microscopic details. Organisms < 1 micron in diameter could not be seen reliably. In objective cytologic studies, overall agreement was recorded on 89 of 99 observations. In the four categories of specimens, observed agreement ranged from 0.778 to 0.958, and kappa was 0.704 to 0.948. For hematology specimens, overall agreement was found on 69 of 80 observations; observed agreement on eight types of nucleated blood cells ranged from 0.5 to 1.0, and kappa was 0.429 to 1.0. Poorer color definition and image quality prevented accurate identification of lymphoblasts and eosinophils in particular. For histologic specimens, overall agreement was obtained on 56 of 66 observations, observed agreement on four categories of histologic change ranged from 0.73 to 0.93, and kappa was 0.47 to 0.9. CONCLUSIONS: The desktop interactive video conferencing system, as configured in this study, was unsuitable for making definitive diagnoses from transmitted microscopic images.

Cell Biology↗

Age-related characteristics of gastric squamous epithelial mucosa in foals.

Specimens of grossly normal gastric stratified squamous epithelial mucosa adjacent to the margo plicatus on the right side and along the greater curvature were obtained from 7 foetuses, 10 term foals and 12 foals 2-35 days old. Gastric squamous epithelium from the foetuses changed markedly during gestation. At 150-270 days, the epithelium was 8-10 cells thick, with a single layer of basal cells. Epithelial cells were polyhedral and had abundant clear or slightly stained cytoplasm. In the 300-day foetus the basal layer was thicker, epithelial cells were polyhedral, and there was a flattened 1 cell-thick layer superficially. In the 335-day foetus, the epithelial cells were flat and there was a superficial layer of keratinised cells, 1-2 cells thick. In term foals, the gastric epithelium consisted of 10-12 cell layers, with 4-5 thin layers of surface keratin. Epithelial projections (papillae) were either absent or not pronounced. The gastric epithelium became thicker with increasing age, including increased epithelial cell layers, thickening of the keratinised layers, and more pronounced papillae. Desquamation was observed in the keratinised layers of gastric squamous epithelium from foals > or = 2 days of age.

Aging↗

Hematologic and serum biochemical effects of long-term administration of anti-inflammatory doses of prednisone in dogs.

Results of routine hematologic and serum biochemical analyses from 12 healthy adult male dogs that were given prednisone (0.55 mg/kg of body weight, PO, q 12 h) for 35 days were compared with those of a control group of 6 dogs that were given gelatin capsules. Analyses were performed at 2-week intervals during and after prednisone administration. Lymphocyte and eosinophil counts were significantly (P less than 0.005) decreased after 2 and 4 weeks of prednisone treatment, compared with controls. Two weeks after treatment, eosinophil counts in prednisone-treated dogs were similar to those of control dogs, whereas lymphocyte counts remained low 4 weeks after treatment in treated dogs (1,869 +/- 145 cells/microliters), compared with that in control dogs (3,662 +/- 548 cells/microliters). Neutrophil and monocyte counts did not significantly change during glucocorticoid administration. Mean platelet volume significantly (P less than 0.001) decreased after 4 weeks of prednisone treatment, but returned to pretreatment values by 2 weeks after treatment. Four weeks of prednisone treatment did not cause significant increased activity in serum alanine transaminase, total alkaline phosphatase or the steroid-induced isoenzyme of alkaline phosphatase. Significant increases in serum albumin (P less than 0.001) and total protein (P less than 0.05) concentrations were detected after 4 weeks of treatment, but mean values were not significantly different from those of controls 2 weeks after treatment ended. Results of our study indicate that eosinophil and lymphocyte counts are the most sensitive indicators of long-term glucocorticoid administration at anti-inflammatory dosages of 1.1 mg/kg daily.

Alkaline Phosphatase↗

Septicemia in vaccinated and nonvaccinated turkeys inoculated with Pasteurella multocida serotype A:3,4.

Sixty-four, 10-week-old turkeys were inoculated with a highly virulent field isolate (86-1913) of Pasteurella multocida serotype A:3,4 by an oculo-nasal-oral route. Inoculated turkeys were examined at 4, 8, 16, 20, and 24 hours post-inoculation for bacteremia and histologic lesions. Bacteremia was detected in one of six turkeys 8 hours after inoculation and in four of six turkey poults at 16 hours post-inoculation. Pasteurella multocida was isolated from the spleens of two turkeys at 8 hours and from the spleens of all six poults 16 hours after inoculation. Peak concentrations of P. multocida reached 10(9) colony forming units per ml of blood. At 4 to 8 hours post-inoculation, isolate 86-1913 produced a fibrinopurulent bronchopneumonia followed by severe pulmonary necrosis, pleuritis, vasculitis; and, at 16 to 24 hours post-inoculation numerous extracellular bacteria were observed. Hepatic lesions included focal heterophil aggregates 8 hours after inoculation; these progressed to hepatic necrosis. Numerous extracellular bacteria within sinusoids were present 16 to 24 hours after inoculation. At 16 to 24 hours post-inoculation, there was degeneration of periarteriolar reticular cells in the spleen; these cells progressed to coalescing coagulative splenic necrosis with extracellular bacterial colonies. A second group of 41, 10-week-old turkeys, previously vaccinated with the Clemson University strain of P. multocida serotype A:3,4, were challenged with isolate 86-1913.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Lymphangiosarcoma and haemangiosarcoma in a cat.

Ultrastructural findings in a feline ventral abdominal vascular tumour showed lack of basal lamina, few micropinocytotic vesicles and intercellular junctions and a discontinuous endothelial cell layer. A splenic cyst had a continuous basal lamina, numerous micropinocytotic vesicles and intercellular junctions and a continuous endothelial cell layer. These findings were compatible with diagnosis of lymphangiosarcoma (ventral abdomen and metastases) and haemangiosarcoma (splenic cyst).

Animals↗

Intermediate filament staining in the cytologic and histologic diagnosis of canine skin and soft tissue tumors.

Formalin-fixed histologic and acetone-fixed cytologic preparations from 87 surgically removed subcutaneous and soft tissue canine tumors were examined for immunoreactivity to cytokeratin, desmin, and vimentin. The avidin-biotin complex (ABC) technique demonstrated immunoreactivity in both preparations, but the intensity and specificity of the reactions were dependent on the primary antibody. Polyclonal antibodies to cytokeratin were more consistent in immunoreactivity than were polyclonal desmin or vimentin antibodies. The monoclonal antibody proved more satisfactory for demonstrating vimentin than the polyclonal antibody. Greater dilutions of primary antibodies may be used on cytologic preparations than on histologic sections. Evaluation of cytologic preparations may be inconclusive due to background staining, scant cellularity, or poor cytoplasmic preservation.

Animals↗

Surgical treatment of epulides in dogs: 25 cases (1974-1984).

Epulides were diagnosed and surgically removed in 25 dogs. Histologic examination of the epulides indicated that 40% (10/25) were acanthomatous, 32% (8/25) were ossifying, and 28% (7/25) were fibromatous. Recurrence of the tumor directly resulted in the death of 2 dogs. One of these dogs died of malnutrition 13 months after removal of an ossifying epulis, and regrowth of an acanthomatous epulis that was not resected completely resulted in malnutrition and death in another dog 6 months after surgery. Malignant transformation was observed in a third dog 6 months after removal of an ossifying epulis when an osteosarcoma developed where the epulis had been removed. The range of survival was 6 to 134 months, mean survival time was 43.1 months, median survival time was 49 months, and 1-year survival rate was 92%. Satisfactory long-term tumor control was achieved by aggressive surgical treatment of epulides.

Animals↗

Basophilic leukaemia in a dog.

Leukaemia in an 11-year-old bitch was characterized by the presence in the peripheral blood and bone marrow of cells with lobulated nuclei and numerous metachromatic cytoplasmic granules. The results of cytochemical stains for peroxidase and naphthol AS-D chloracetate esterase activity were negative. Ultrastructurally, the cytoplasmic granules were finely granular with no membranous coils or crystalline lattice structures. Based on these findings, the neoplastic cells were classified as basophils.

Animals↗

Tracheal carcinoma in a dog.

Tracheal carcinoma was diagnosed in a 10-year-old male Spitz dog suffering from dyspnoea. The tumour was poorly differentiated, but desmosomes were seen by transmission electron microscopy.

Animals↗

Immunohistochemical demonstration of desmin in canine smooth muscle tumors.

Sections of formalin-fixed, paraffin-embedded canine leiomyomas, leiomyosarcomas, or fibrosarcomas were examined by immunohistochemical methods for the presence of desmin. Twenty-two leiomyomas and leiomyosarcomas were stained using the avidin-biotin complex technique, and 14 samples demonstrated positive staining for desmin. The eight negative results obtained may reflect differences in fixation or the affinity of the primary antibody for the tissues examined. Desmin was specific for myogenic tissues. Five canine fibrosarcomas examined immunohistochemically were all negative for desmin staining. The results indicate that desmin is a useful marker for immunohistochemical identification of canine leiomyomas and leiomyosarcomas.

Animals↗

Heparin-induced agglutination of erythrocytes in horses.

Heparin was administered subcutaneously 2 times a day for 4 days to 5 horses. An additional group of 5 horses was used as time-matched controls. Significant decreases in PCV, erythrocyte count, and hemoglobin concentration were observed during heparin therapy. The mean corpuscular volume (MCV) of the heparin-treated horses increased to a peak value of 66.1 fl on the last day of treatment. Erythrocyte creatine concentration and glucose 6-phosphate dehydrogenase activity increased moderately during the treatment. These data indicated that the rapid, profound increase in MCV during heparin therapy was not primarily a result of release of large immature erythrocytes from the bone marrow. A second experiment was subsequently performed, using 3 horses. These horses were given heparin 2 times a day, as was done in the first experiment. Saline wet mounts of erythrocyte suspensions were examined once a day for the presence of agglutination. Cell suspensions were examined with or without exposure to a dilute trypsin solution, and erythrocyte counts were done on each suspension, using an electronic cell counter. Agglutination of erythrocytes was evident on the first day of treatment and became more pronounced as treatment progressed. Exposure to trypsin solution reversed the agglutination. The apparent erythrocyte count decreased and MCV increased sharply in the samples processed normally, but there was little change in those suspensions exposed to trypsin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Erythrocyte agglutination associated with heparin treatment in three horses.

In vitro erythrocyte agglutination developed in 3 hospitalized horses receiving heparin treatment. The agglutination caused artifactual decreases in erythrocyte counts and increases in mean corpuscular volume (MCV) values. Treatment of cell suspensions with trypsin eliminated the agglutination and the changes in erythrocyte count and MCV. Similar abnormalities in erythrocyte counts and MCV have been reported in healthy horses treated with heparin and have been cited as evidence of hemolysis and regenerative anemia.

Animals↗