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Biomedical subjects

W B Morrison

Publications and source records attributed to W B Morrison.

At least 55 records · Page 3Linked to original sources
PubMed1994

Evaluation of prognostic factors for dogs with synovial sarcoma: 36 cases (1986-1991).

Medical records of 36 dogs with synovial sarcoma confirmed by microscopic examination of H&E-stained sections of tissue were selected for retrospective analysis from dogs admitted between 1986 and 1991 to participating institutions of the Veterinary Cooperative Oncology Group. Metastasis was evident at the time of diagnosis in 8 (22%) dogs, and 15 (41%) dogs ultimately developed metastatic tumors. Median survival time for all dogs, as determined by life-table analysis, was 17 months. For dogs that were subsequently treated and became tumor free, the median disease-free interval was 30 months. Nine dogs had previously had localized excision attempted, but all had recurrence of the tumor locally (median, 4.5 months). Of 29 dogs that underwent amputation, including the 9 with localized recurrence, 2 had tumor recurrence on the amputation stump. Most dogs had survival time and disease-free interval of > 36 months after amputation. Four dogs that had received chemotherapy for tumors of advanced clinical stages did not respond to treatment. One dog that had received locally applied radiotherapy after localized excision did not have evidence of tumor recurrence 2 years after radiotherapy. Clinical stage, histologic grade, and a positive result for tests that used cytokeratin immunohistochemical staining significantly (P < 0.05) influenced survival time and disease-free interval. Analysis of data for the study reported here suggested that histologic criteria can be an excellent predictor of dogs that are likely to have tumor recurrence after amputation and that would most likely benefit from aggressive treatment with adjuvants.

Amputation, Surgical↗
PubMed1994

Confirmation of a pulmonary component of multicentric lymphosarcoma with bronchoalveolar lavage in two dogs.

Histologic examination of lung tissue has been the only definitive diagnostic procedure used to confirm pulmonary involvement with lymphosarcoma (LSA) in dogs. Lung involvement with LSA was diagnosed by cytologic examination of bronchoalveolar lavage fluid in 2 dogs with multicentric LSA. Both dogs had cough or dyspnea, in addition to peripheral lymphadenopathy or visceral organomegaly. Both dogs had nonspecific, abnormal thoracic radiographic findings, including diffuse pulmonary interstitial pattern, hydrothorax, and mediastinal and retrosternal lymphadenopathy. In these 2 dogs, postmortem lung histologic examination, performed immediately after bronchoalveolar lavage, confirmed the cytologic diagnosis of pulmonary infiltration with LSA.

Animals↗
PubMed1994

Evaluation of Cu-PTSM as a tracer of tumor perfusion: comparison with labeled microspheres in spontaneous canine neoplasms.

Copper-62-labeled Cu-PTSM is a promising generator-produced PET tracer for myocardial, cerebral and renal perfusion. To evaluate whether [62Cu]Cu-PTSM could also serve as a blood flow tracer in PET studies of tumor tissue, the tumor uptake of [62Cu]Cu-PTSM was examined in dogs with spontaneously-occurring soft-tissue neoplasms. Copper-67-labeled Cu-PTSM was administered intravenously to four anesthetized dogs, followed c. 5 min later by a left ventricular injection of 85Sr-labeled microspheres (15 microns) to provide an independent measure of tumor perfusion. Forty-seven tumors (average weight = 2.5 +/- 3.7 g) were obtained and sectioned into 80 samples. The correlation of 67Cu-PTSM uptake with regional renal perfusion was also examined in data from 395 tissue samples ranging in flow from 0.02 to 9.39 mL min-1 g-1. Rates of tumor perfusion assessed with 85Sr-labeled microspheres ranged from 0.011 to 3.0 mL min-1 g-1. No correlation was found between tumor size and the rate of tumor perfusion. However, an excellent linear correlation exists between tumor perfusion calculated from [62Cu]Cu-PTSM data and tumor perfusion measured with 85Sr-microspheres (r = 0.94 for 80 samples), suggesting that [62Cu]Cu-PTSM may be useful as a radiopharmaceutical for PET studies of tumor perfusion.

Animals↗
PubMed1994

Plantar fibromatosis: a benign aggressive neoplasm with a characteristic appearance on MR images.

PURPOSE: To define the magnetic resonance (MR) imaging characteristics of plantar fibromatosis. MATERIALS AND METHODS: Sixteen patients (19 feet) with proved plantar fibromatosis underwent preoperative MR imaging at 1.5 T. A control group of 19 people (24 feet) also underwent MR imaging. RESULTS: Twenty-seven lesions (mean size, 2.2 x 1.0 cm) were identified. All had infiltrative upper margins. Four (15%) of the 27 grew deep to the aponeurosis; 25 (92%) exhibited some signal intensity heterogeneity. All 27 of the lesions on T1-weighted conventional spin-echo (SE) images, seven (78%) of the nine on T2-weighted conventional SE images, and 17 (94%) of the 18 on T2-weighted fast SE images were isointense to minimally hyperintense (to the signal intensity of adjacent muscle). Five (83%) of the six lesions on short inversion time inversion-recovery images were hyperintense. Enhancement was variable on contrast material-enhanced images; nine (60%) of the 15 lesions on these images showed marked enhancement. CONCLUSION: Plantar fibromatosis is a benign but infiltrative neoplasm with a characteristic location and appearance on MR images.

Contrast Media↗
PubMed1994

Flow cytometric DNA ploidy analysis in canine transitional cell carcinoma of urinary bladders.

Flow cytometric analysis of DNA ploidy was performed on 51 formalin-fixed, paraffin-embedded samples of canine transitional cell carcinoma of the urinary bladder. The DNA ploidy data obtained were compared to several clinicopathologic features. In addition, the DNA ploidy of 15 hyperplastic/inflamed and 8 normal canine urinary bladders was measured. Forty-three of the 51 neoplastic samples had interpretable DNA histograms. DNA aneuploidy was found in 34/43 (79%) of the transitional cell carcinoma samples. Of the 34 aneuploid neoplasms, 16 (47%) were hyperdiploid, 17 (50%) were tetraploid, and 1 (3%) was hypertetraploid. No significant correlation was found between the presence of DNA aneuploidy and the growth pattern, histologic grade, clinical stage, or individual morphologic features of this neoplasm. Additionally, the DNA ploidy was not related to the sex, age, or survival time of dogs with transitional cell carcinoma. All of the normal and all but one of the hyperplastic/inflamed urinary bladders were diploid. The results from this study demonstrated that DNA ploidy can be measured from paraffin-embedded canine samples by flow cytometry, a majority of the canine transitional cell carcinomas were aneuploid, and a significant correlation did not exist between the DNA ploidy and specific clinicopathologic features of this neoplasm.

Animals↗
PubMed1993

Cytologic analysis of bronchoalveolar lavage fluid from 47 dogs with multicentric malignant lymphoma.

Bronchoalveolar lavage (BAL) was performed in 47 dogs with multicentric malignant lymphoma (ML). Cytologic results were evaluated, and ability to detect pulmonary involvement with ML, using BAL, was compared with ability to detect pulmonary involvement, using thoracic radiography and tracheal wash. Lung lobes were considered to be involved with ML on the basis of BAL fluid findings if morphologically abnormal lymphocytes were present in the fluid. Total nucleated cell count, relative lymphocyte count, and absolute lymphocyte count were greater (P < 0.001) in BAL fluid from dogs with multicentric ML than in BAL fluid from histologically normal dogs. Pulmonary involvement with ML was detected by BAL fluid cytologic examination in 89 of 135 lung lobes lavaged (66%). Lung lobes involved with ML were from 31 of the 47 dogs with multicentric ML (66%). Radiographic abnormalities supportive of pulmonary parenchymal involvement with ML were detected in 16 of the 47 dogs (34%). Of these 16 dogs, 15 (94%) had pulmonary involvement with ML on the basis of BAL fluid cytologic findings. Tracheal wash fluid contained abnormal lymphocytes in 4 of 41 dogs (10%). In all 4 dogs, BAL fluid also contained abnormal lymphocytes. Cytologic evaluation of BAL fluid was more sensitive in detecting pulmonary involvement with ML, compared with radiographic evaluation of the lungs or tracheal wash.

Animals↗
PubMed1993

Diagnosis of osteomyelitis: utility of fat-suppressed contrast-enhanced MR imaging.

PURPOSE: To assess the value of fat-suppressed contrast material-enhanced magnetic resonance (MR) imaging in the diagnosis of osteomyelitis. MATERIALS AND METHODS: T1- and T2-weighted MR imaging was performed in 51 cases of suspected osteomyelitis. Nonenhanced and contrast-enhanced T1-weighted fat-suppressed MR images were also obtained. Three-phase bone scan results were available for 30 cases. Complicating clinical factors, including chronic osteomyelitis (n = 26), postoperative state (n = 17), and neuropathic disease of the foot (n = 5), were identified in 73% of cases. RESULTS: In the diagnosis of osteomyelitis, scintigraphy demonstrated a sensitivity of 61% and specificity of 33%. For nonenhanced MR imaging, sensitivity was 79% and specificity was 53%. For fat-suppressed contrast-enhanced imaging, sensitivity was 88% and specificity was 93%. CONCLUSION: In diagnosing osteomyelitis in patients with complicating clinical factors, fat-suppressed contrast-enhanced MR imaging was significantly more sensitive than scintigraphy (P = .04) and significantly more specific than nonenhanced MR imaging (P = .02) or scintigraphy (P = .008).

Adipose Tissue↗
PubMed1993

Advantages and disadvantages of cytology and histopathology for the diagnosis of cancer.

Histopathology and cytology are both valuable diagnostic tools. An appreciation of the virtues and the limits of each technique is essential if the user is to avoid mistakes in interpretation. It is also important to take full advantage of the many additional techniques that can be applied to cytology smears and histopathology tissue sections to gain maximum clinical information.

Animals↗
PubMed1992

Bromide toxicosis (bromism) in a dog treated with potassium bromide for refractory seizures.

A 4-year-old German Shepherd Dog was evaluated because of chronic hind limb lameness and recurrent seizures. Diagnostic evaluation of the dog confirmed rheumatoid arthritis and idiopathic epilepsy. The rheumatoid arthritis was treated with prednisone and piroxicam. The seizures were treated with phenobarbital plus clonazepam. The seizures were refractory and potassium bromide was substituted for clonazepam. The dog was reevaluated 4 months after initiation of potassium bromide treatment because of recurrence of arthritis signs. During hospitalization, the dog had neurologic signs, which progressed from depression to recumbency and stupor. Anisocoria, muscle pain, and hyporeflexia were noticed. Bromide toxicosis was diagnosed on the basis of toxic serum bromide concentration (2.7 mg/ml; therapeutic range, 1.0 to 2.0 mg/ml). Following cessation of potassium bromide treatment, the neurologic signs resolved. The seizures recurred 6 weeks after potassium bromide was discontinued. Bromide treatment was reinitiated at half the initial dosage. After 6 weeks, the serum bromide concentration was 1.9 mg/ml, and no seizures had been reported by the dog's owners. Therapeutic serum bromide concentrations in dogs has been reported to be 0.5 to 2.3 mg/ml. The serum bromide concentration at which toxic signs are expected is variable in human beings because individuals differ in their tolerance of the drug. Clinical trials are necessary to determine the toxic serum bromide concentrations in dogs. This case of bromism in a dog suggests that the dosage of potassium bromide should be based on serial measurement of serum bromide concentrations.

Animals↗
PubMed1991

Cytosine arabinoside chemotherapy for acute megakaryocytic leukemia in a cat.

Myeloproliferative disease in a cat was characterized by severe, nonregenerative anemia, circulating blast cells, and proliferation of bizarre megakaryoblasts in the bone marrow. The number of circulating platelets was markedly higher than normal at initial examination. Chemotherapy with cytosine arabinoside was successful in inducing complete remission and maintaining survival for 122 days.

Animals↗
PubMed1991

Vincristine-induced peripheral neuropathy in a dog.

A 12-year-old spayed Golden Retriever with mycosis fungoides was treated by use of a chemotherapy protocol that included vincristine. After 16 weekly vincristine injections, the dog began to have signs of peripheral neuropathy. Results of electromyographic examination were consistent with muscle denervation, and motor nerve conduction velocity was depressed. Histologic examination of a common peroneal nerve biopsy specimen revealed severe nerve fiber degeneration. Clinical response and pathologic evidence of improvement were observed after the drug had been discontinued for 2.5 months.

Animals↗
PubMed1991

Bleomycin chemotherapy for metastatic squamous cell carcinoma in a ferret.

Bleomycin, an antitumor antibiotic, was effective in temporarily reducing the size of a metastatic squamous cell carcinoma in a ferret. The tumor had recurred after previous excision and had metastasized to the right submandibular lymph node. The ferret was treated without effect at a dosage of 10 U/m2, sc, once a week. The dosage was increased to 20 U/m2 once a week, and reduction of tumor size was observed.

Animals↗
PubMed1990

Orally administered clonidine as a secretagogue of growth hormone and as a thymotrophic agent in dogs of various ages.

The growth hormone (GH) secretagogue activity of variable dosages of clonidine (16.5, 50, 150, and 450 micrograms/kg of body weight), given orally mixed with the daily food ration, was evaluated in young and old dogs. Significant (P less than 0.05) increase in plasma GH concentration was detected at all dosages tested in young dogs and in response to all but the lowest dose tested in the old dogs fed the clonidine-containing diet. Old dogs had plasma GH concentration that exceeded that of young dogs when higher doses of clonidine were used. A clonidine (100 micrograms/kg)-supplemented diet was fed to middle-aged dogs twice daily for 30 days. Significant (P less than 0.01) increase of plasma GH concentration was observed on the first day of the feeding trial, but was undetectable by day 30. After feeding the clonidine-enhanced diet for 30 days, the effects on thymic morphology were variable, and there was no effect on plasma thymulin titer. Clonidine-fed dogs had significantly increased lymphocyte blastogenic responsiveness to mitogens, compared with that of control dogs, when evaluated as stimulation index.

Administration, Oral↗
PubMed1989

Diagnosis and treatment of cancer in aged animals.

Considerable morbidity can be associated with cancer and the diagnosis and treatment of cancer. Knowledge of a tumor's likely clinical behavior and an awareness of the benefits and morbidity associated with treatment will help the clinician and the owner find the most appropriate plan of action for the aged pet with cancer. Tumor cell heterogeneity is a concept of enormous importance in our understanding of neoplasia. Phenotypic variations within cancer cell populations often confound our attempts to cure a patient's cancer. Frequently, we are forced to settle for palliative therapy when our patient's cancer has advanced beyond our ability to rescue.

Aging↗
PubMed1987

Assessment of neutrophil function in dogs with primary ciliary dyskinesia.

Compared with neutrophils from healthy dogs, neutrophils from 2 dogs with primary ciliary dyskinesia had increased distance of random migration, but fewer of the neutrophils migrated. The affected dogs had an increase in the numbers of Staphylococcus aureus phagocytized. Lymphocyte blastogenesis in the affected dogs in response to standard mitogens was considered to be normal.

Animals↗
PubMed1987

Microtubular protofilaments and subunits of the outer dynein arm in cilia from dogs with primary ciliary dyskinesia.

Using a procedure of membrane solubilization followed by tannic acid fixation-staining, we found abnormally constructed central and B microtubules in cilia from dogs with primary ciliary dyskinesia. We also found that a ciliary abnormality commonly associated with primary ciliary dyskinesia, "shortened outer dynein arms," actually represents the absence of a specific set of the 3 peripheral subunits that make up the outer dynein arms. We believe that this is the first time that these have been reported. Because the proximal subunits of the outer dynein arm are present and attached to the A microtubule, we argue that in these patients there is no structural abnormality of the A microtubule or the A-tubule attachment sites for outer and inner arms and radial spokes. Also, because a majority of cilia in these patients were motile, we believe that the data from this study support the concept that the outer dynein arms are not required for some motion but probably required for normal motility; however, the central microtubules, central microtubular complex, and probably the B tubules are essential for motility.

Adenosine Triphosphatases↗