Establishment of a cell line with associated Epstein-Barr-like virus from a leukemic orangutan.

An Epstein-Barr virus like herpesvirus has been isolated from a lymphoid cell line derived from an orangutan with spontaneous myelomonocytic leukemia. Herpesvirus has not previously been isolated from this species of higher ape.

FeLV epidemiology in Los Angeles cats: Appraisal of detection methods.

We investigated the reliability of the fixed cell indirect fluorescent antibody (IFA) peripheral blood smear test as an index of systemic infection with FeLV. Positive results with this test were found to correlate well with detectable FeLV p30 antigen in bone-marrow smears by IFA, in serum and tissue by competition immunoassays, and with type-C particles in bone marrow or spleen by electron microscopy. Most cats with lymphoma, anemia or infectious peritonitis were positive for FeLV and showed a poor or absent antibody response to FeLV p30, gp70, and FOCMA antigens. Most older cats with lymphoma, carcinoma, or sarcoma were negative for FeLV expression and also lacked these FeLV-related antibodies. Detectable immunologic response to FeLV p30 and gp70 proteins and a high-titered FOCMA antibody response were generally restricted to certain healthy cats exposed to FeLV. Antibody to endogenous RD-114 viral p30 and gp70 was not detected in any of a large number of feline sera tested. The prevalence of FeLV-related diseases and immunologic responses to FeLV in healthy cats was directly correlated with the degree of FeLV exposure. By using the IFA blood smear and FOCMA antibody tests one can monitor the horizontal spread of FeLV in multi-cat household and accurately predict the FeLV disease susceptibilty or resistance of individual cats in each environments.

Human bladder carcinoma: characterization of two new tumor cell lines and search for tumor viruses.

Two newly established human bladder carcinoma cell lines, designated HT-1197 and HT-1376, were characterized. Cells of both cultures exhibited fine structural microvilli and tonofibrils indicative of their epithelial origin. In addition, desmosomes were also present in HT-1197. Marker chromosomes present in HT-1197 and HT-1376 distinguished these from each other and from other known human tumor cell lines. Both cultures grew in soft agar, induced fibrinolytic activity, and were tumorigenic in mice and hamsters. No type C or other virus expression was detected in these cell lines nor in other human urothelial tumors tested.

The epidemiology and virology of C-type virus-associated hematological cancers and related diseases in wild mice.

In several different populations of wild mice, observed over a 35-month period in laboratory geriatric colonies, a direct correlation was found between the prevalence and titer of spleen complement-fixing gs (p30) antigen and C-type particles in newly trapped healthy mice and a predilection to lymphoma and a hind leg paralytic disease upon aging. Other studies have established the indigenous C-type virus as the essential etiological determinant of both diseases in wild mice. An increased incidence of breast carcinomas, hepatomas, and pulmonary adenomas associated with C-type virus also occurred in the lymphoma-paralysis-prone colony as compared with the tumor-resistant colonies.

Lower motor neuron disease in wild mice caused by indigenous type C virus and search for a similar etiology in human amyotrophic lateral sclerosis.

In certain genetically susceptible populations of wild mice a progressive motor neuron disease with a long latent period is caused by indigenous type C leukemia virus. Neuronal damage appears to be due primarily to a direct neurotropic effect of the virus and not to an immunogenic mechanism. The disease can be prevented by antiviral genetic means. Search for a similar virus in humans with ALS has been negative.

Childhood sarcomas and lymphomas. Characterization of new cell lines and search for type-C virus.

Four cell lines were derived from childhood malignancies: rhabdomyosarcoma, sarcoma, lymphosarcoma and an American Burkitt's lymphoma. Cells of the four lines formed tumors in immunosuppressed newborn hamsters. The tumors had a microscopic appearance like that of the tumors from which the cell lines were derived. No virus-like particles were detected by electron microscopy in the cell lines after treatment with bromodeoxyuridine; no hamster type-C virus expression was present in cell lines derived from the hamster tumors. Chromosome constitution and in vitro growth properties of the cell lines were studied as was the fibrinolytic function of the sarcoma lines.

Mammary tumor virus particles in the submaxillary gland, seminal vesicle, and nonmammary tumors of wild mice.

Type-B mammary tumor virus particles were detected by electron microscopy in the submaxillary glands of 6 of 27 freshly trapped, pregnant wild mice (Mus musculus). Type-B particles were also detected in 3 9f 24 seminal vesicles and 2 pulmonary adenomas from wild mice. Intracytoplasmic type-A virus particles were found in 7 spontaneous nonmammary tumors (lymphoma, hepatoma, lung adenoma) of aging wild mice. Type-C virus particles were also detected in many of these tissues.

Induction of disseminated virulent cytomegalovirus infection by immunosuppression of naturally chronically infected wild mice.

Wild mice immunosuppressed with antithymocytic sera show a high incidence of disseminated virulent cytomegalovirus infection.

Isolation of a neurotropic type C virus.

A neurogenic paralysis of the lower limb can be induced and serially transmitted in mice by a nontransforming type C virus strain that originated in an embryo of a wild mouse. The virus exerted a neurotropic effect on the anterior horn neurons.