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Biomedical subjects

D W Dalgard

Publications and source records attributed to D W Dalgard.

34 records · Page 2Linked to original sources
PubMed1979

Surgical technique for a permanent tracheostomy in Beagle dogs.

A surgical procedure to produce a permanent tracheostomy in dogs was developed. The procedure consisted of dissecting portions of the cartilaginous rings free from the underlying tracheal mucosa, cutting through the mucosa and suturing the mucosa to the skin. The procedure was performed in approximately 30 minutes and resulted in a permanent, maintenance-free, mucocutaneous stoma that also permitted breathing through the upper respiratory airways.

Animals↗
PubMed1978

Experimental infection of chimpanzees with the Norwalk agent of epidemic viral gastroenteritis.

A fecal filtrate of human origin containing the Norwalk agent of epidemic viral gastroenteritis was administered by stomach tube to chimpanzees in an attempt to induce diarrheal disease. Significant postchallenge serum antibody rises against Norwalk viral antigens were demonstrated in all animals using the techniques of immune electron microscopy and radioimmunoassay. In addition, viral antigens were detected in feces from five of nine animals using radioimmunoassay. Clinical illness characterized by diarrhea and/or vomiting did not occur. Infection was transmitted subsequently by feeding four additional chimpanzees a fecal filtrate prepared from one of the previously infected animals. Development of an antibody response in four animals and detection of viral antigen in two animals that received this passage filtrate indicated that viral replication had occurred in the absence of clinical illness. The availability of the chimpanzee as an experimental animal host susceptible to infection with the Norwalk agent should facilitate the study of epidemic viral gastroenteritis.

Animals↗
PubMed1978

Carcinogenic and other adverse effects of procarbazine in nonhuman primates.

The carcinogenic potential of procarbazine is under investigation in three species (Macaca mulatta, Macaca fascicularis, and Cercopithecus aethiops) of nonhuman primates. A total of 55 monkeys have received procarbazine s.c., p.o., or i.p. for periods of up to 12 years. Eleven of the 42 monkeys (26%) necropsied thus far have had malignant neoplasms, 6 of which were acute leukemia. Two monkeys developed osteogenic sarcomas, two monkeys developed hemangiosarcomas, and a single case of lymphocytic lymphoma was found. The average total dose of procarbazine received by the monkeys developing cancers was 36.0 g; the average duration of procarbazine treatment was 75 months. A number of the toxic effects of procarbazine seen in humans were also noted in this series of monkeys, including vomiting and myelosuppression. Another striking toxic effect was on the reproductive system of the males. The majority of the adult males necropsied to date have had testicular atrophy with complete aplasia of the germinal epithelium.

Animals↗
PubMed1976

Carcinogenicity of aflatoxin B1 in rhesus monkeys: two additional cases of primary liver cancer.

Three of 42 (7%) monkeys given aflatoxin B1 (AFB1) for longer than 2 years have developed primary malignant neoplasms of the liver. Liver biopsies performed at intervals during aflatoxin administration revealed that neoplasia was preceded by pathologic lesions of the liver, including toxic hepatitis, proliferation of pseudotubules, and hyperplastic nodules. Serum alpha-fetoprotein levels, monitored in one of the monkeys by radioimmunoassay, paralleled tumor growth and recurrence of the hepatocellular carcinoma. Normal serum alpha-fetoprotein levels were noted for a monkey with hemangioendothelial sarcoma. Our results implicate AFB1 as a liver carcinogen in monkeys and add additional support to the hypothesis that humans exposed to this substance may be at risk of developing liver cancer.

Aflatoxins↗
PubMed1975

Nonhuman primate models for lymphoma, leukemia, and other neoplasms.

Herpesvirus saimiri (HVS) is an oncogenic virus for a variety of nonhuman primates. HVS does not produce overt disease upon inoculation in the natural host (squirrel monkey) but consistently induces neoplasms including lymphomas and lymphocytic leukemias in 4 other species of monkeys. Various drugs inhibit replication of HVS in vitro including cytosine arabinoside and adenine arabinoside. In addition, the lymphoma and leukemia induced in owl monkeys responds to vincristine and prednisolone, cyclophosphamide, cytosine arabinoside, and human interferon. Of the various chemical carcinogens studied, the antitumor agent procarbazine induces neoplasms in a variety of species including monkeys. Thus far this compound has induced acute myelogenous leukemia (AML), lymphoma, and hemangiosarcomas in macaques. We have induced primary liver tumors in macaques with several nitrosamines and aflatoxin B1 and these tumors produce alpha-fetoprotein (AFP) which can be assayed for both diagnosis and therapy. Thus far, therapy of hepatocellular carcinoma has been most successful with surgical resection; and the tumor mass and serum AFP have been less responsive to single agent chemotherapy. These nonhuman primate models are useful for an understanding of the cause, diagnosis, prevention, and treatment of the human disease.

Animals↗
PubMed1975

Diaphragmatic herniation of the liver in macaques demonstrated by intravenous hepatography.

A suspected diagnosis of diaphragmatic herniation of the liver in 2 monkeys (Macaca fascicularis and Macaca mulatta) was confirmed radiographically by using various contrast media. Experimental compound AG 60.99, which is selectively concentrated in the liver and spleen, allowed excellent visualization of these 2 organs and confirmed the presence of a portion of the liver in the right thorax. Cholografin Meglumine was subsequently utilized to determine the location of the gall bladder. Other potential uses for AG 60.99 were discussed.

Animals↗
PubMed1973

Mycoplasma hyorhinis swine arthritis. 3. Modified disease in Piney Woods swine.

Piney Woods miniature swine, when injected with Mycoplasma hyorhinis, develop an acute arthritis. The disease in these animals is limited clinically, microbiologically, and pathologically to a mild acute illness without the more chronic and destructive features noted in a previous study of the experimental disease in Yorkshire swine.

Acute Disease↗