No abstract

No abstract

Endogenous retroviral particles (ERVs) have been detected in the genome of all eukaryotes. They are generally non-pathogenic except in mice where they have been found to induce tumors and immunological disorders. The ERVs have morphological features consistent with type-C retroviral particles and are commonly expressed in normal placental villous tissues. ERVs may have a role in the regulation of placental gene expression, syncytiotrophoblast formation, or pregnancy-related immunosuppression. In this study, well-characterized antibodies (monoclonal and polyclonal antibodies) raised against retroviral proteins (anti-HIV and anti-SIV) and endogenous retroviral (ERV) particles were assessed for their cross-reactivity (by using immunohistochemistry) with normal baboon placental and other adult tissues. The monoclonal antibodies to exogenous retroviral proteins (anti-HIV-2 gp120, anti-HIV-1 gp41, anti-SIVmac p27, anti-HIV-1 RT, and anti-HIV-2 core protein) showed specific immunohistochemical reactivity with the syncytiotrophoblast. Antibodies to endogenous retroviral gene products (anti-ERV3 env, anti-HERV-K RT, and anti-HERV-K env) also reacted in a similar manner and did not cross-react with other adult tissues. These studies have shown that retroviral-cross-reactive proteins are expressed in baboon placental syncytiotrophoblast and may have a role to play at the feto-maternal interface.

SUMMARY:The histology and the ultrastructure of the uterine glands of the lesser bushbaby (Galago senegalensis) were studied in six specimens (5 pregnant and one non pregnant) which were fixed partly with bouin's fixative and part with 2.5% glutaraldehyde in 0.1 M cacodylate buffer. An overview of the main results revealed uterine glands in the non-pregnant uterus are rudimentary and scarce within the mucosa. In early pregnancy (first trimester) the uterine glands profiles appear in clusters. In late stage pregnancy (third trimester) the uterine gland profiles appear opposite chorionic vesicles. In the later stages of gestation maternal glandular epithelium consisted mainly of simple columnar epithelium. The cells had abundant flattened cisternae of granular endoplasmic reticulum usually with an apical-basal orientation. Their nuclei had abundant euchromatin relative to the amount of heterochromatin. They also had a prominent Golgi apparatus quite characteristic of protein synthesizing cells. The basal plasmalemma was thrown into infoldings that have the effect of increasing the surface area across which nutrients could pass from the maternal circulation and are secreted by the cell as histiotrophe. Both physiologic hypertrophy and hyperplasia of the uterine glands are observed to occur with advancement of pregnancy.