Molecular prevalence of Bartonella, Babesia, and hemotropic Mycoplasma species in dogs with hemangiosarcoma from across the United States.

Hemangiosarcoma (HSA), a locally invasive and highly metastatic endothelial cell neoplasm, accounts for two-thirds of all cardiac and splenic neoplasms in dogs. Bartonella spp. infection has been reported in association with neoplastic and non-neoplastic vasoproliferative lesions in animals and humans. The objective of this study was to determine the prevalence of Bartonella spp. in conjunction with two other hemotropic pathogens, Babesia spp. and hemotropic Mycoplasma spp., in tissues and blood samples from 110 dogs with histopathologically diagnosed HSA from throughout the United States. This was a retrospective, observational study using clinical specimens from 110 dogs with HSA banked by the biospecimen repository of the Canine Comparative Oncology and Genomics Consortium. Samples provided for this study from each dog included: fresh frozen HSA tumor tissue (available from n = 100 of the 110 dogs), fresh frozen non-tumor tissue (n = 104), and whole blood and serum samples (n = 108 and 107 respectively). Blood and tissues were tested by qPCR for Bartonella, hemotropic Mycoplasma, and Babesia spp. DNA; serum was tested for Bartonella spp. antibodies. Bartonella spp. DNA was amplified and sequenced from 73% of dogs with HSA (80/110). In contrast, hemotropic Mycoplasma spp. DNA was amplified from a significantly smaller proportion (5%, p<0.0001) and Babesia spp. DNA was not amplified from any dog. Of the 100 HSA tumor samples submitted, 34% were Bartonella PCR positive (32% of splenic tumors, 57% of cardiac tumors, and 17% of other tumor locations). Of 104 non-tumor tissues, 63% were Bartonella PCR positive (56% of spleen samples, 93% of cardiac samples, and 63% of skin/subcutaneous samples). Of dogs with Bartonella positive HSA tumor, 76% were also positive in non-tumor tissue. Bartonella spp. DNA was not PCR amplified from whole blood. This study documented a high prevalence of Bartonella spp. DNA in dogs with HSA from geographically diverse regions of the United States. While 73% of all tissue samples from these dogs were PCR positive for Bartonella DNA, none of the blood samples were, indicating that whole blood samples do not reflect tissue presence of this pathogen. Future studies are needed to further investigate the role of Bartonella spp. in the development of HSA.

First description of Bartonella koehlerae infection in a Spanish dog with infective endocarditis.

BACKGROUND: Bartonella koehlerae has been recently described as a new cat- and cat fleas-associated agent of culture-negative human endocarditis. It has been also encountered in one dog from Israel and six dogs from the USA, but other clinically relevant reports involving this bacterium are lacking. RESULTS: A 7-year-old intact male mixed dog presented with clinico-pathological signs consistent with mitral endocarditis and cutaneous hemangiosarcoma. Molecular studies revealed the presence of Bartonella koehlerae DNA in samples from blood and mitral valve tissue. CONCLUSIONS: This is the first description of B. koehlerae in Spain, corroborating that it can also be detected in dogs. Bartonella koehlerae infection should also be considered in Spain in humans and dogs presenting with clinical disease suggestive of it, such as culture-negative endocarditis.

Superinfected cutaneous angiosarcoma: a highly malignant neoplasm simulating an inflammatory process.

This report describes a patient with a poorly differentiated cutaneous angiosarcoma (CA) of the face superinfected with pseudomonas aeruginosa. Neoplastic cells were positive for CD-34, CD-31 and vimentin, whereas they failed to express other vascular markers such as Factor VIII and Ulex europeaus lectin. The tumor spread rapidly through the skin and the superficial soft tissue before metastasizing. The patient died of disease 6 months after histopathological diagnosis. An autopsy revealed widespread metastases in the lung and the liver. The aim of this report is to call attention to some circumstances in which CA may masquerade as an inflammatory process, delaying the right diagnosis with serious consequences for the patient.

Sequences from myeloblastosis-associated virus MAV-2(O) and UR2AV involved in the formation of plaques and the induction of osteopetrosis, anemia, and ataxia.

Recombinant viruses were made between myeloblastosis-associated virus MAV-2(O) and UR2AV to examine the relationship between regions of the MAV-2(O) genome and disease induction. The env-long terminal repeat (LTR) portion of MAV-2(O), when substituted into UR2AV, was sufficient to induce osteopetrosis identical to that caused by the parent MAV-2(O). When this region was reduced to the gp37 and LTR of MAV-2(O), osteopetrosis more severe than that caused by the parent virus was induced. Recombinant viruses that contained all or part of the MAV-2(O) env gene in the absence of the MAV-2(O) LTR induced a severe, chronic anemia and late-onset osteopetrosis, leading to the conclusion that the MAV-2(O) LTR, in addition to env, was required for rapid induction of osteopetrosis. A viral recombinant, pEU, which contained the gp85 segment of UR2AV substituted into MAV-2(O), induced an ataxia/cerebellar dysfunction not seen during infection with the other chimeric or parent viruses. In vitro studies of the parent and recombinant viruses demonstrated that the ability to form plaques on chicken embryo fibroblasts correlated with the presence of the MAV-2(O) gp37 and LTR except for construct pEU. When the viruses were inoculated into 10-day-old chickens, chimeras containing the env-LTR of gp37-LTR region of MAV-2(O) induced severe regenerative anemia similar to that induced by MAV-2(O). pEU was the exception, suggesting that the unique configuration of this chimera is responsible for its unusual pathogenic properties.

Unique sequences in the env gene of avian hemangioma retrovirus are responsible for cytotoxicity and endothelial cell perturbation.

An avian retrovirus isolated from spontaneous cavernous hemangiomas of layer hens codes for an env protein that induces a cytopathic effect on a wide variety of cultured avian and mammalian cells and also causes thrombogenicity of endothelial cells. Sequence analysis of the avian hemangioma inducing virus revealed unique elements in both its env gene and its LTR. We propose that these elements are responsible for the biological and pathogenic characteristics of the virus.

Envelope glycoprotein of avian hemangioma retrovirus induces a thrombogenic surface on human and bovine endothelial cells.

Vascular endothelial cells are a target for blood-borne pathogens which may affect their integrity and thromboresistant properties. Here, we report that cultured bovine and human endothelial cells lose their thromboresistance following interaction with the avian hemangioma-inducing retrovirus. We show that the envelope (env) gene product, glycoprotein 85, is responsible for this effect, which appears soon after infection without viral replication or cell transformation. Induction of thrombogenicity is associated with a reduction in prostacyclin release and increased expression of tissue factor. These observations may explain the occurrence of thrombosis frequently observed in association with the hemangiosarcomas induced by avian hemangioma-inducing retrovirus. These unique endothelial cell-virus interactions may also be a model for the pathogenesis of various vascular diseases.

Histopathologic studies on myeloproliferative sarcoma virus (MPSV) induced leukemias and hemangiosarcoma in Jar-2 rats.

It is well known that MPSV induces myeloproliferative syndrome (MPS) in mice. Intravenous one shot inoculation of myeloproliferative sarcoma virus (MPSV) with Friend murine leukemia virus (F-MuLV) as a helper in newborn Jar-2 rats (on the second neonatal day) yielded hematopoietic malignancies in all the treated rats (25/25 rats) after 2 weeks' latency. MPS appeared from the 14th day in 14 rats. In the midst of the myeloproliferative field of the spleen and bone marrow, myeloblastic or myeloblastic-erythroblastic foci were observed. From 19th day, acute myeloblastic leukemia occurred in 3 rats and erythroleukemia in 8 rats. MPSV induced first MPS which remained as such or later developed into acute leukemia. Myelofibrosis as seen in mice was not observed. In addition, hemangiosarcoma of the brain, spinal cord and spleen appeared in 15 rats from the 24th day, and were often multiple. MPSV can yield the tumor only in newborn rats, and target cells of MPSV are not only hematopoietic cells but also endothelial cells of the brain, spinal cord and occasionally spleen.

Biologic and molecular characterization of two newly isolated ras-containing murine leukemia viruses.

A murine sarcoma virus (MSV) was recovered from an (NFS X NS.C58v-1) F1 mouse which developed splenic sarcoma and erythroleukemia 6 months after inoculation with a mink cell focus-inducing murine leukemia virus (MuLV) isolated from an NFS mouse infected with a wild mouse ecotropic MuLV. The MSV, designated NS.C58 MSV-1, induced foci of transformation in mouse and rat fibroblasts, and inoculation of mice of various strains 2 weeks of age or younger resulted in erythroleukemia and sarcomatous lesions in spleen, lymph node, and brain. The MSV provirus was molecularly cloned from a genomic library prepared from transformed non-producer rat cells. The 8.8-kilobase proviral DNA contained a 1.0-kilobase p21 ras coding segment which replaced most of the gp70-encoding portion of an MuLV, most likely the endogenous C58v-1 ecotropic virus. The ras oncogene is closely related to v-Ha-ras by hybridization, expression of p21 protein, and nucleotide sequence. It is nearly identical in sequence to v-bas, the only previously described transduced, activated mouse c-ras. At position 12 in the p21 coding region, arginine is substituted for the naturally occurring glycine present in c-ras. A second MSV isolate is described which is similar to NS.C58 MSV-1 except for a 100- to 200-base-pair deletion in the noncoding region of the ras-containing insert.

Papillomavirus infection in cattle: viral and chemical cofactors in naturally occurring and experimentally induced tumours.

Six different types of bovine papillomavirus (BPV-1 to BPV-6) have been identified and classified into two subgroups: subgroup A, which induce fibropapillomas, and subgroup B, which induce true epithelial papillomas. BPV-4, a member of subgroup B, is the aetiological agent of papillomas of the upper alimentary canal, which can become a focus for transformation to squamous-cell carcinomas in animals feeding on bracken fern. Strong circumstantial evidence suggests that the progression to malignancy is due to the interplay between BPV-4 and carcinogen(s) present in the fern. The carcinomas of the upper alimentary canal are often accompanied by adenomas and adenocarcinomas of the lower bowels, and by carcinomas and hemangiosarcomas of the urinary bladder. Bracken-grazing animals are also heavily immunosuppressed. Florid papillomatosis of the upper alimentary canal and cancers of the urinary bladder have been experimentally reproduced in animals either kept on a diet of bracken or immunosuppressed with azathioprine. Several bladder cancers contained multiple episomal copies of BPV-2 DNA, suggesting that this virus, or its genome, can be present in a latent form, and that it can be implicated in malignant transformation. Further indication of latent infection is provided by the onset of skin warts in papillomatosis-free animals. These warts developed at sites of damaged skin and harboured either BPV-1 or BPV-2. BPV-4 DNA has not been found in the naturally occurring cancers of the upper alimentary canal and of the lower bowels, except in one tongue carcinoma and one transforming papilloma, indicating that the viral genome is not required for the maintenance of the malignant state in the alimentary canal.

Vascular tumors induced by polyoma virus in pregnant rats.

Female R rats mated with an R male and inoculated in utero with polyoma virus after "fetectomy" developed tumors. These tumors originated in the uterus and were of fetal origin (visceral yolk sac). Histologically, they were hemangiomas or hemangiosarcomas. The latter were transplantable and grew in tissue culture. Infectious polyoma virus could not be isolated from the tumor cells kept as transplantable lines or cultured in vitro. However, the tumor cells were positive for the polyoma-specific surface antigen, polyoma tumor-specific transplantation antigen(s), and polyoma nuclear T antigen.

Particles with RNA of high molecular weight and RNA-directed DNA polymerase in human brain tumors.

We have previously shown that neoplastic cells of human breast cancers, leukemias, lymphomas, and sarcomas contain particles similar to the viruses that have been established as etiologic agents of these diseases in mice. The present paper concerns tumors of the central nervous system for which no suitable animal model or corresponding virus exists. Nevertheless, using the simultaneous detection test, we showed that human brain tumors contain 70S RNA and RNA-directed DNA polymerase encapsulated in a particulate component possessing a density of 1.17 g/ml. These particles satisfy the three diagnostic criteria that characterize RNA tumor viruses of animals. 24 Out of 26 (92%) of the most malignant (glioblastoma and medulloblastoma) brain tumors examined contained these virus-like entities.