Observations of apparent C-type particles in baboon (Papio cynocephalus) placentas.

Ultrastructural investigations have revealed the presence of apparent endogenously derived C-type particles in the placental villi of each of 13 baboons studied. Both budding and mature forms were observed in the syncytiotrophoblast of these animals at various stages of pregnancy.

Oncornavirus: isolation from a squirrel monkey (Saimiri sciureus) lung culture.

An oncornavirus isolated from a squirrel monkey (Saimiri sciureus) lung culture has a density of 1.16 to 1.17 grams per milliliter, contains 70S RNA, and has an RNA-directed DNA polymerase that prefers Mg2+ over Mn2+ in an assay in which polyribocytidylate - oligodeoxyguanylate (12-18) is used as a synthetic template. Morphologically, the virus resembles Mason-Pfizer monkey virus but is antigenically distinct from this virus. The virus grows in cells of human, chimpanzee, rhesus monkey, canine, and mink origin, but not cells of squirrel monkey origin. On the basis of its properties, the newly isolated virus can be classified as a retravirus.

Comparison of Mason-Pfizer monkey virus and squirrel monkey (Saimiri sciureus) retrovirus by immunoelectron microscopy.

Comparison of Mason-Pfizer monkey virus and squirrel monkey retrovirus (both candidate type D oncornaviruses) by immunoelectron microscopy revealed that these two viruses do not share common surface antigens.

A x C rat prostate adenocarcinoma: initial characterization of testosterone regulation of hormone receptors of cultured cancer cells and derived tumors.

A x C rat prostate cancer cells were established in continuous culture. The polygonal epithelial cells had granular cytoplasm and well-defined cell margins, contained round to oval nuclei with prominent nucleoli, and were tumorigenic when inoculated into A x C male rats. The tumors produced by the injected prostate cancer cells grew as well-vascularized, solid, cribriform adenocarcinomas. The rat prostate cancer cells and derived tumors contained cytoplasmic and nuclear androgen receptors and prolactin receptors. Androgen regulation of prolactin receptor content and androgen receptor distribution in A x C rat prostate cancer cells were comparable to those of the normal ventral prostate gland. These studies suggest that the A x C rat prostate cancer cells and tumors may represent a unique model for studies of hormonal regulation of prostate cancer cell behavior.

C-type viruses in chimpanzee (Pan sp.) placentas.

C-type virus particles were observed by electron microscopy in placentas from 7 of 9 chimpanzees (Pan sp.). These viruses were morphologically similar to those observed in placentas of other primates.

Squirrel monkey retrovirus and Herpesvirus saimiri: observation in the same cell following isolation.

Electron microscopic examination of mink lung cells previously cultured with a squirrel monkey (Saimiri sciureus) throat swab suspension revealed the presence of squirrel monkey retrovirus (SMRV) and Herpesvirus saimiri (HVS) coexisting within the same cells in culture. HVS was identified by serum neutralization, and the retrovirus isolate was identified as SMRV by a morphologic examination, microimmunodiffusion analysis, and demonstration of an Mg2+ preference for the RNA-directed DNA polymerase.

Autogenous humoral immunity to baboon xenotropic endogenous type C virus.

A radioimmune precipitation assay was used to evaluate the humoral immune response of baboons (Papio cynocephalus) to their endogenous, xenotropic, type C (M7) virus. Using 125I or [3H]leucine-labeled intact virus preparation, we demonstrated that baboons possess naturally occurring virus-binding antibodies to this virus. Antibody appeared directed against envelope and not internal viral proteins. Immunoglobulins responsible for virus-binding were predominant in the IgG and IgA serum fractions, whereas IgM participated to a minor degree. The biologic activities of these immunoglobulins were investigated by means of a focus reduction assay for virus neutralization with a murine sarcoma virus (M7) pseudotype. We determined that, despite the presence of considerable virus binding, none of the normal baboon sera tested possessed neutralizing activity for M7 virus.

Oncorna-like viruses in baboon prostate tissue.

Oncorna-like virus particles were observed in prostate tissue of 2 of 11 baboons inoculated 3 years previously with a chemical carcinogen. There were no indications, however, of any relationship between the carcinogen and the development of virus particles. Biopsy specimens from the animals showed no evidence of neoplasia, and electron microscopic examination suggested that this virus should be categorized as a B-type oncornavirus.

Oncornavirus-like particles in squirrel monkey (Saimiri sciureus) placenta and placenta culture.

Oncornavirus-like particles similar in morphology to type D particles were observed in 1 of 2 squirrel monkey (Saimiri sciureus) placentas. Intracytoplasmic type A particles, immature virus particles, and mature viruses with eccentric or occasionally centric nucleoids were associated with placental syncytiotrophoblasts. A spike layer typical of type B viruses was not detected in viral envelopes. Onvornaviruses, identical to those previously isolated from squirrel monkey tissues and similar to Mason-Pfizer monkey virus, were seen in cultures derived from the virus-positive squirrel monkey placenta cocultivated with a mink lung culture. The major morphologic difference between the in vivo and the in vitro squirrel monkey virus was in the nucleoid position of mature virus particles.

Oncornavirus-like particles in baboon type C virus-infected chimpanzee lung cells (SFRE:CL-1).

Intracytoplasmic type A particles were observed in a fetal chimpanzee lung culture (SFRE:CL-1) inoculated with type C virus-containing supernatants from a coculture of baboon placenta and SFRE:CL-1 cells. Budding, immature, and mature type C particles were also noted. In thin section, spike-like structures were rarely detected on budding intracytoplasmic type A particles but were occasionally observed on some immature and mature virus particles. Unlike mouse mammary tumor virus or Mason-Pfizer monkey virus, infected SFRE:CL-1 cells contained no eccentric or rodshaped nucleoids.

Vertical transmission of C-type viruses: their presence in baboon follicular oocytes and tubal ova.

C-type viruses were found in baboon follicular oocytes and tubal ova adjacent to the plasma membrane in the perivitelline space or along the inner margin of the zona pellucida. Their presence support the concept of vertical transmission of C-type viruses.

Chemical inhibition of foamyvirus in primary baboon (Papio cynocephalus) kidney cells.

This report describes the conditions for the use of aluminum chloride (AlCl3) in growth and maintenance media for the suppression or inhibition of simian foamyviruses (SFV) in primary baboon kidney (BAK) and rabbit kidney (RK) cell cultures. When RK cells were planted in medium containing AlCl3, infected with SFV, and passaged, the growth of SFV was suppressed or inhibited by the presence of AlCl3. With this method, BAK cells yielded higher viral titers after infection with various viruses, thus making these cells more suitable for virological applications.

The collection of blood on filter paper and its use in the dot-immunobinding assay (DIA) for detection of antibody.

The ability to collect whole blood directly onto filter paper pre-cut to the size used in the dot-immunobinding assay (DIA) is a practical adjunct to this procedure. Its applicability for field studies is suggested.

Ultrastructure of cleavage stages and preimplantation embryos of the baboon.

The baboon preimplantation stages were examined using light and electron microscopy. Six cases were studied at 2, 3, 4, 5, 7 and 8 days estimated fertilization age. The first 3 specimens were composed of 2, 8 and 24 blastomeres respectively. At 5 days, 30 to 40 cells were counted and more than 60 cells in later stages. Primitive "trophoblast cells" differentiate at 7 days and a crescentic blastocoele appears at 8 days. Shedding of the zona pellucida is not observed in the 7 and 8 day specimens. The preimplantation period is longer in the baboon than in man. C-type viruses are observed in the zona pellucida, in the perivitelline and interblastomeric spaces. Microvilli and caveolae cover ther periphery of the baboon conceptus. As in many other mammals, transformation of the mitochondria, changes in the ribosomes distribution, multivesicular bodies, myelin figures, nucleoli and intranuclear clusters of granules are described in the baboon. Cytoplasmic fibrous strands are not present as in the mouse. Experiments on the influence of hormones and drugs on ultrastructural changes would help to evaluate the importance of biohazards during the early development of primates.

AXC rat prostatic adenocarcinoma: characterization of cells in culture.

We have described the establishment of AXC rat prostatic cancer cells in continuous culture. When injected into isogeneic male rats, these cells produce prostatic adenocarcinomas. The response of androgen and prolactin receptors and ODC in LSC-AXC prostatic cancer cells and tumors to androgen ablation is indistinguishable from that of ventral prostate. In addition, LSC-AXC prostatic tumors retain levels of secretory acid phosphatase comparable to those of ventral prostate of aged AXC rats. These data demonstrate that LSC-AXC prostatic cancer cells and tumors retain a high degree of differentiation, androgen regulated function. The LSC-AXC prostatic cancer cells and tumors appear to represent a unique model system for combined in vivo and in vitro studies of androgen regulation of prostate cancer cell function.

The chemotactic, phagocytic, and microbial killing abilities of primate polymorphonuclear leukocytes (PML).

Functions of polymorphonuclear leukocytes including chemotaxis, phagocytosis, and microbial killing were investigated in baboons (Papio cynocephalus), cebus monkeys (Cebus apella), and marmosets (Saguinus oedipus). Cells from a group of normal adult human volunteers were also studied for comparison. Polymorphonuclear leukocytes from the three nonhuman primate species were comparable to each other and to humans in chemotactic activity using endotoxin activated serum. In addition, the ability of blood leukocytes to ingest and kill microorganisms was investigated using a new fluorochrome microassay. Leukocytes of all non-human primates were competent in phagocytosing bacteria, but leukocytes from cebus monkeys and marmosets ingested candida organisms poorly. Compared to humans, all nonhuman primates exhibited poor killing of the microbes.

Sensitivity of equine herpesviruses 1 and 3 in vitro to a new nucleoside analogue, 9-[[2-hydroxy-1-(hydroxymethyl) ethoxy] methyl] guanine.

The following members of the Herpetoviridae family were tested to determine their sensitivities to the new antiviral drug, BIOLF-62: equine herpesvirus types 1 and 3, human herpesvirus types 1 and 2, swine herpesvirus, bovine herpesvirus type 4, feline herpesvirus, canine herpesvirus, and herpes simiae virus. Equine herpesviruses 1 and 3, human herpesviruses 1 and 2, and herpes simiae virus were all sensitive to BIOLF-62 at concentrations of less than 0.55 micrograms/ml. Equine herpesvirus types 1 and 3 were particularly sensitive, viral median effective dose (ED50) concentrations of the drug being only 0.033 and 0.16 micrograms/ml, respectively. Such high antiviral potency and low cell toxicity indicate that BIOLF-62 might be useful in the treatment of infected animals.

Experimental Herpes neonatalis in SA 8-infected baboons (Papio cynocephalus).

13 newborn baboons were experimentally infected with a baboon-derived herpesvirus SA 8-strain. Intratracheal infection produced herpetic tracheobronchopneumonia, intravenous inoculation resulted in adrenal necrosis similar to that in human neonatal herpes infection.