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Biomedical subjects

A E Friess

Publications and source records attributed to A E Friess.

At least 55 records · Page 3Linked to original sources
PubMed1981

The placenta of the pig. II. The ultrastructure of the areolae.

The ultrastructure of the areolae in the porcine placenta is described. The areolae occur on day 30 of pregnancy as dome-shaped formation over the openings of the uterine glands. The lumen of the areolae is filled with the secretions of the uterine glands, the so-called histiotroph. The areolae lining epithelium is high collumnar, possessing long microvilli, a well-developed apical tubular system and numerous coated vesicles. This indicates that the epithelium has a high absorptive capacity. Our histochemical investigations reveal a high content of glycoproteins within the areolar lumen. The importance of one of the glycoprotein components of the histiotroph, uteroferrin, is discussed in connection with iron transfer from mother to the fetus.

Animals↗
PubMed1980

The placenta of the pig. I. Finestructural changes of the placental barrier during pregnancy.

The finestructural changes of the interareolar porcine placenta during pregnancy are described. After perfusion fixation of the placenta the change in the thickness of the placental barrier from day 30 to day 110 of gestation is much more evident than after immerson fixation as has been used by all former authors. The alterations are due to the indentation of both the trophoblast and uterine epithelium by their corresponding capillary-network. This indentation is limited to the lateral wall and the summit of the chorionic ridges, while at the base the trophoblast as well as the uterine epithelium remains high columnar. This indicates that in the interareolar porcine placenta, which is represented by the chorionic ridges and the corresponding endometrial folds, at least two different areas with different structure and function may be discerned. 1) The lateral side and the top of the chorionic ridges seem to be predestinated for gaseous exchange. The placental barrier in this area is often less than 2 micrometers. 2) The transport of blood-borne nutrients takes place at the base of the chorionic ridges. This transport seems to be facilitated by an intercellular channel system between the uterine epithelial cells.

Animals↗
PubMed1978

The uterovaginal sperm host glands of the quail (Coturnix coturnix japonica): an ultrastructural and ultracytochemical study.

Ultrastructural and ultrahistochemical studies were performed on the uterovaginal sperm host glands of the quail (Coturnix coturnix japonica). The proximal parts of the glandular necks are lined by a pseudostratified epithelium, consisting of high columnar ciliated cells and small, irregular shaped, basal cells. The true glandular epithelium is composed only of columnar cells with microvilli on their luminal end. A characteristic luminal feature is a large lipid droplet in the perinuclear region. In the subplasmalemmal region numberous tubular profiles are seen which could represent a cellular resorption system. To evaluate the absorptive capacity of the uterovaginal sperm host glands, tracer studies with HRP, ferritin, lanthanum and ruthenium red were undertaken. Since between 5 min and 3 h after injection no absorption could be found with the techniques mentioned, it is suggested that phagocytosis of spermatozoa by the glandular epithelium is not likely to occur.

Absorption↗
PubMed1977

Macrophage-lymphocyte cluster formation in the medullary sinus of lymph node after immunization with sheep red blood cells (SRBC).

Normally the lymphatic sinuses of the lymph node are loosely packed with lymphocytes and free macrophages as well as with macrophages adhering to the fibrocellular trabeculae. After immunization with SRBC cluster formation occurs in the medullary sinuses of rats between a central macrophage and peripherally located lymphocytes. These rosette-like clusters are nearly identical with the clusters found during primary and secondary immune response against SRBC in vitro and seem to be the in vivo equivalent for the same immune response.

Animals↗
PubMed1976

[Electron microscope localization of thiamine pyrophosphatase and nucleoside diphosphatase in lymphocytes].

In ductus thoracicus lymphocytes of the rat the localization of specific phosphatases was studied by means of ultrahistochemistry. Thiaminepyrophosphatase was found in the outer lamellae of the Golgi-field as well as in lysosomes, whereas nucleosiddiphosphatases could be localized on the plasma membrane at low pH. These findings are correlated with the phaenotype of B- and T-lymphocytes. Their functional significance is discussed.

Animals↗