| Epstein-Barr virus (EBV) infection of humans has been associated with the development of lymphoid malignancies mainly of B-cell lineage, although occasionally T-cell lymphomas have been reported. We describe here the characterization of a novel EBV-like virus (HV(MNE)) isolated from a simian T-cell lymphotropic virus type I/II (STLV-I/II) seronegative pigtailed macaque (macaca nemestrina) with a cutaneous T-cell lymphoma. immunohistochemistry studies on the skin lesions demonstrated that the infiltrating cells were of the CD3( )/CD8( ) phenotype. Two primary transformed CD8( ) T-cell lines were obtained from cultures of peripheral blood mononuclear cells (PBMC) and skin, and, with time, both cell lines became interleukin-2-independent and acquired the constitutive activation of STAT proteins. polymerase chain reaction analysis of the dna from the cell lines and tissues from the lymphomatous animal demonstrated the presence of a 536-bp dna fragment that was 90% identical to EBV polymerase gene sequences, whereas the same dna was consistently negative for STLV-I/II sequences. Electron microscopy performed on both cell lines, after sodium butyrate treatment, showed the presence of a herpes-like virus that was designated HV(MNE) according to the existing nomenclature. in situ hybridization studies using EBV Epstein-Barr viral-encoded rna probes showed viral RNA expression in both CD8( ) T-cell lines as well as in the infiltrating CD8( ) T cells of skin-tissue biopsies. Phylogenetic analysis of a 465-bp fragment from the polymerase gene of HV(MNE) placed this virus within the lymphocryptovirus genus and demonstrated that HV(MNE) is a distinct virus, clearly related to human EBV and other EBV-like herpesviruses found in nonhuman primates. ( info) |
2/5. adenocarcinoma in the rectum of a capped langur (Presbytis pileata). A rectal adenocarcinoma in a 22-year-old capped langur histologically resembling those in human cases is reported. An ill-defined diffuse tumor with fibrously firm rectal wall showed diffuse infiltrative growth of signet-ring cancer cells. immunohistochemistry demonstrated positive staining for CEA, lysozyme, EMA, keratin and B72.3. ( info) |
3/5. Histochemical and immunohistochemical similarities between hepatic tumors in two chimpanzees and man. A well-differentiated trabecular hepatocellular carcinoma (HCC) and a well-differentiated tumor resembling HCC from each of two chimpanzees were found to have histochemical and immunohistochemical staining characteristics similar to those in human HCCs. transforming growth factor alpha was overexpressed in both tumors. Oval cells, thought to be liver stem cell progeny with a possible role in hepatocarcinogenesis, were observed among nontumorous hepatocytes, particularly near the tumors. Hepatic tumors are rare in chimpanzees but their similarities to human HCC provides a useful research model. ( info) |
| This report documents asymptomatic infections of mycobacterium kansasii in four of five tuberculin positive squirrel monkeys (saimiri sciureus sciureus). The mycobacterial dna amplified by polymerase chain reaction (PCR) from a bronchial lymph node had no affinity for the species specific probes of M. tuberculosis, M. avium, and M. intracellulare, thus allowing the presumptive diagnosis of an atypical mycobacterial infection. Infection by mycobacterium kansasii was confirmed by culture of bronchial lymph nodes from three monkeys. The source of the infection was never identified. ( info) |
| A spontaneous colonic adenocarcinoma and endometriosis was diagnosed in a 34-year-old female rhesus macaque (macaca mulatta). The tumor caused partial obstruction of the ascending colon and histologically resembled the commonly described napkin-ring tumors of the descending and sigmoid colon found in humans. serum levels of CA 125, a high-molecular-weight glycoprotein antigen that has been reported elevated in a variety of pathological conditions of the pelvic cavity in humans, was severely elevated. Both the adenocarcinoma and the endometriosis may have contributed to this finding. ( info) |