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Biomedical subjects

H W Casey

Publications and source records attributed to H W Casey.

At least 37 records · Page 2Linked to original sources

Malignant mammary tumors in beagle dogs dosed with investigational oral contraceptive steroids.

Of 172 beagle dogs administered investigational oral contraceptive steroids for 2.4-5.2 years, 9 developed malignant mammary tumors. At necropsy their ages varied from 41 to 70 months, with a mean age of 4.9 years. The malignant tumors were observed in 1 dog that received ethynerone plus mestranol at 1.05 mg/kg/day and in 4 dogs that received chlorethynyl norgestrel plus mestranol at 1.05 mg/kg/day. Also, 4 dogs that received anagestone acetate plus mestranol at either 0.44 or 1.10 mg/kg/day developed malignant mammary tumors. Malignant tumors were not seen in 33 dogs administered mestranol at 0.02 and 0.05 mg/kg/day for 7 years or in 18 dogs given ethynerone without mestranol at 1.00 mg/kg/day for 5 years. No malignant tumors were observed in 18 control dogs maintained for 7 years without treatment. Three dogs had single malignant mammary nodules, 3 dogs had 2 malignant nodules, 2 dogs had 4-6 malignant nodules, and 1 dog in the treatment group given high dosages of ethynerone plus mestranol had 14 mammary nodules composed of fibrosarcoma. The malignant tumors were histologically classified as 5 anaplastic carcinomas, 2 solid carcinomas, 1 tubular adenocarcinoma, 1 squamous cell carcinoma, and 1 fibrosarcoma. Most dogs had only 1 histologic type of cancer (8/9 dogs); however, 1 dog had carcinomas of both solid and anaplastic types involving different glands. Metastases were present in 5 dogs and most often involved regional lymph nodes and lung.

Adenocarcinoma↗

Histopathologic evidence for parvovirus infection in dogs.

Two dogs kenneled at a commercial establishment died of a disease manifested as severe hemorrhagic diarrhea. Histopathologic findings in both dogs bore a striking resemblance to those typical of feline infectious enteritis. Viral particles resembling members of the Parvoviridae family were observed in the contents of the small intestine of one of the dogs. The disease was similar to the recently recognized canine gastroenteritis associated with a parvovirus-like agent.

Animals↗

Mammary nodules in beagle dogs administered investigational oral contraceptive steroids.

Of 172 beagle dogs administered oral contraceptive steroids for 5-7 years, 114 developed 1,156 nodules in the mammary gland region. Most of these nodules arose 2.5-3.5 years after initiation of treatment. Approximately 16% of the nodules were transient and disappeared spontaneously from the mammary gland during the study. A total of 925 nodules were present in 99 dogs at the time of death or necropsy. These nodules were classified as benign mammary dysplasias (7.0%), lobular or intraductal hyperplasias (31.4%), simple adenomas (20.8%), complex adenomas (25.4%), benign mixed tumors (5.3%), malignant tumors (3.6%), or nonmammary lesions (6.5%). Histologically, the mammary nodules were representative primarily of the hyperplasias and tumors that occur spontaneously in the mammary glands of the dog. The only major exception was the presence of 82 simple adenomas that had basaloid features. Most of the contraceptive-related mammary nodules developed in dogs receiving the combination of progestion and mestranol at 10 or 25 times the proposed human dosage. Control dogs and dogs receiving mestrenol alone had few mammary nodules. Combinations of anagestone acetate and mestranol and chloroethynyl norgestrel (WY-4355) and mestranol produced large numbers of nodules at 10 and 25 times the proposed human dosage, whereas ethynerone plus mestranol produced large numbers of nodules only at 25 times the proposed human dosage. Ethynerone, when given alone at 25 times the proposed human dosage, was associated with fewer mammary nodules. Malignant neoplasms were seen in dogs given 10 and 25 times the proposed human dosage of anagestone acetate plus mestranol and 25 times the proposed human dosage of WY-4355 plus mestranol and ethynerone plus mestranol. This study strongly associates certain combinations of progestin and mestranol with mammary neoplasia in dogs.

Adenoma↗

Cerebral granular cell tumor (myoblastoma) in a dog: case report and literature review.

An infiltrative granular cell tumor (myoblastoma) occurred in the superficial parieto-occipital cortex of an ataxic 12-year-old dog. The neoplasm was characterized by cells with numerous small PAS-positive, diastase-resistant cytoplasmic granules. The neoplasm also had numerous cells with large globular PAS-positive bodies (angulate bodies). Ultrastructurally, the neoplastic cells were characterized by numerous homogenous electron-dense, sharply bounded granules and large pleomorphic, indistinctly bounded granules. The angulate bodies were composed of 8- to 10-nm fibrils, a few of which formed parallel arrays or tubule-like structures. This represents the first report of a granular cell tumor in the central nervous system of the dog.

Animals↗

Amebiasis in goldfish.

Five cases of amebiasis were diagnosed in goldfish (Carassius auratus) from home aquariums and from a laboratory aquarium. Granulomas containing amoebae were in many organs but were most numerous in kidneys. Because there were pseudopods, food vacuoles, vesicular nucleoli and other ultrastructural characteristics of the organisms, we identified the organisms as amoebae. On the basis of mitotic stages it is possible they belong in the family Hartmannellidae.

Amebiasis↗

Lymphosarcoma in an infant northern fur seal (Callorhinus ursinus).

An infant northern fur seal (Callhorinus ursinus) died in a rookery on St. Paul Island, Pribilof Islands, Alaska. Grossly, slight enlargement of the mesenteric lymph nodes was seen. Microscopically, a lymphosarcoma composed of sheets of monomorphic lymphoid cells in sections of lymph node and tonsil was seen. Electron microscopy of formalin-fixed tissues revealed several structures that were possible of viral origin in the cytoplasm of the neoplastic cells.

Animals↗

Toxoplasmosis in a California sea lion (Zalophus californianus).

Disseminated toxoplasmosis was diagnosed in a female California sea lion that had been used in thermoregulation studies for about 4 years while housed in a small enclosure with a fresh-water pool at the University of Hawaii, Honolulu. Toxoplasma gondii was demonstrated in and around necrotic lesions of the heart and the stomach. Source of the infection was not established; however, studies on toxoplasmosis in cats were being conducted at the institution, and common caretakers attended both groups of animals.

Animals↗

Thymomas in domestic animals.

A retrospective study of 15 thymomas in domestic animals showed four animals had antemortem signs of dyspnea and grossly visible lumps in the thoracic inlet. The neoplasms were single, multilobulated, encapsulated masses in the anterior mediastinum or thoracic inlet. Cells with clear cytoplasm comprised the bulk of two canine thymomas, whereas the remaining neoplasms had a mixed population of ovoid and spindle-shaped cells. There were lymphocyte populations of varying density in all thymomas. Three thymomas contained structures similar to hyalinized cells and Hassall's corpuscles of normal thymus. Metastatic lesions were not seen but there were implantations on the pericardium in one cat. There was capsular invasion in the ovine thymomas.

Animals↗

Membranous glomerulonephritis in dogs infected with Dirofilaria immitis.

Membranous glomerulonephritis was diagnosed in five dogs with patent Dirofilaria immitis infections. Electron-dense deposits were present on the epithelial side of the glomerular basement membrane. An immunofluorescent study demonstrated immunoglobulins in the capillary wall and mesangium of the glomeruli. The glomerular lesions were considered to represent an immune complex form of glomerulonephritis induced by the D. immitis infection.

Animals↗

Glossitis of military working dogs in south Vietnam; histopathologic observations.

Glossitis, known clinically as "redtongue," was studied in tissues from 34 military working dogs (MWD) in the Republic of Vietnam. This condition was manifested grossly by loss of lingual papillae on the dorsal margins of the rostral third of the tongue. Microscopically, the principal lesions consisted of loss of filiform papillae, hemorrhage and edema in the lamina propria, acanthosis, and cellular infiltration. The cause of glossitis remains unknown at this time.

Animals↗