No abstract

Using the immunoperoxidase technique, we studied "serosal balls," which have features resembling those of cells from primary and metastatic tumors, and may thus complicate cytodiagnosis. Serosal balls were detected in 32 (18%) of 174 peritoneal washings. The balls consisted of oval clusters of cells in solid masses surrounded by flattened cells. The interior of the serosal balls was stained green with Papanicolaou method, showing the presence of homogeneous amorphous material, sometimes stained in a filamentous pattern. Almost all serosal balls were stained immunocytochemically for both keratin and vimentin. The interior was stained with antibodies against collagen types I and III. Therefore, these balls were fragments of serous membrane, and contained fibrous tissue and mesothelial cells.

No abstract

Feline immunodeficiency virus (FIV) infection in cats has been reported to be a useful animal model for human AIDS studies, especially in the early stages of infection. We examined the temporal changes in provirus detection in peripheral blood mononuclear cells (PBMC) and the distribution of FIV-DNA and RNA in feline tissues by the polymerase chain reaction at 10, 35, 70 days after intravenous inoculation of FIV. Viral DNA in the PBMC was detected three to four weeks after infection and its fluctuation was demonstrated for the first time. Ten days after infection, before seroconversion, proviruses were detected only in the mesenteric lymph nodes and intestines. At 35 and 70 days after infection, after seroconversion, proviruses were detected in most lymphoid organs and the salivary glands, but the expression of FIV-RNA was limited to the thymus at 70 days after infection. These results show that FIV-RNA is transcribed from proviral DNA exclusively in the thymus at this stage. We suggest that the quantitative changes in detectable proviruses in the PBMC depend on the relation between the decrease in infected cells caused by cytolytic T lymphocytes and/or apoptosis and their increase caused by the release of a new supply of lymphocytes from the thymus.