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Biomedical subjects

S L Beam

Publications and source records attributed to S L Beam.

5 recordsLinked to original sources

Combined-type osteosarcoma in a rhesus macaque.

A femoral mass from a 15-year-old rhesus macaque was evaluated. Grossly, the mass consisted of a large, osteolytic focus in the distal femur, a gelatinous core of neoplastic tissue in the medullary cavity, and an invasive mass-obliterating musculature of the thigh. On histopathologic evaluation, three neoplastic mesenchymal cell populations, osteoblasts, fibroblasts, and primitive mesenchymal cells were identified. The mass was diagnosed as a combined type osteosarcoma. To our knowledge, this is the first osteosarcoma in a rhesus macaque with this subclassification.

Amputation, Surgical↗

An immunohistochemical study of cyclooxygenase-2 expression in various feline neoplasms.

Cyclooxygenase (COX) enzymes catalyze the synthesis of prostaglandins and exist as two isoforms, COX-1 and COX-2. COX-2 is a potent inducible mediator of inflammation. COX-2 is also upregulated in several human tumors and in canine squamous cell, renal cell, and transitional cell carcinomas, prostatic adenocarcinoma, and intestinal neoplasia. The purpose of this study was to determine whether COX-2 is expressed in various feline tumors. Results of this study may help determine whether COX-2 is a potential target for therapeutic and preventive strategies in cats. Immunohistochemical studies were performed on paraffin-embedded tissues using the amplified streptavidin-biotin-horseradish peroxidase system. COX-2 was found in 7 of 19 (37%) feline transitional cell carcinomas and in 2 of 21 (9%) feline oral squamous cell carcinomas. No COX-2 immunoreactivity was detected in cutaneous squamous cell carcinomas (6), adenocarcinomas (nine mammary, eight pulmonary, seven intestinal), lymphomas (six nasal, six intestinal), or 10 vaccine-associated sarcomas. The widespread absence of COX-2 expression in most feline neoplasms might suggest that COX-2 inhibitors would have a low potential as anticancer agents.

Adenocarcinoma↗

Mapping bovine herpesvirus type 1 latency-related RNA in trigeminal ganglia of latently infected rabbits.

Here we have used the bovine herpesvirus type 1 (BHV-1) rabbit model together with in situ nucleic acid hybridization to identify and map viral RNA present in latently infected neurons. Radioactively labeled cloned HindIII fragments representing most of the BHV-1 genome (Cooper strain) were individually hybridized to sections of trigeminal ganglia taken from rabbits during acute and latent stages of infection. Whereas all viral genomic fragments hybridized to lytically infected tissue culture cells and to acutely infected ganglia, only HindIII fragment D (map units 0.734 to 0.842) hybridized to latently infected ganglionic neurons. Additional in situ hybridization experiments using subcloned fragments of HindIII-D further mapped the latency-related viral RNA to a 1.9-kilobase region (map units 0.734 to 0.748) of the viral genome. These results indicate that BHV-1 gene transcription is restricted during the latent phase of infection; further, they suggest that specific viral transcription may be involved in establishment or maintenance of latent BHV-1 infection.

Animals↗