Search PubMed⌕ Search

Biomedical subjects

W P Jollie

Publications and source records attributed to W P Jollie.

At least 19 recordsLinked to original sources
PubMed1990

Development, morphology, and function of the yolk-sac placenta of laboratory rodents.

A review of current knowledge of the unusual structure and several functions of the yolk-sac membranes of common laboratory rodents, viz., rats, mice, hamsters, guinea pigs and gerbils, enables a better assessment of the significance of this maternofetal exchange system in the experimental production of congenital anomalies. The anatomy of both visceral and parietal walls of the rodent yolk-sac placenta--specifically the anatomical relationships of each wall with maternal and with other fetal tissues--depends on the mode of origin and subsequent development of the yolk sac in these several species. Accordingly, the developmental biology of the rodent yolk sac is described. Since both fine structure and anatomical relationships also determine in large measure the functioning of the membrane as a whole in the absorption of selected materials either for intracellular digestion or for cellular translocation and transport to the developing embryo, the anatomy of the yolk sac is considered in detail. Similarly, since available evidence strongly suggests that teratogenic agents induce perturbations in the cellular mechanisms that control these several functions of the yolk-sac placental system in the production of birth defects, additionally an account is given of the cell biology of the membrane, i.e., endocytosis and targeting/trafficking of materials either for digestion within the epithelium at the maternal surface of the visceral yolk sac or for translocation across the yolk-sac membrane as a whole.

Animals↗
PubMed1990

Effects of sustained dietary ethanol on the ultrastructure of the visceral yolk-sac placenta of the rat.

The present investigation reports ultrastructural alterations in endodermal epithelial cells of the rat visceral yolk-sac placenta that accompany alcohol-induced changes in intracellular trafficking of endocytosed maternal serum proteins. Fine structural changes include restructuring of mitochondrial cristae (foliate to vesicular and tubular forms), beading of cisterns of granular endoplasmic reticulum, hypertrophy and hyperplasia of Golgi elements, differentiation of the Golgi membranes to a GERL configuration, and a notable increase in numbers of primary lysosomes. Such changes in ultrastructure suggest that exposure of this developing maternofetal exchange system to high levels of ethanol in maternal blood increases the production of primary lysosomes near term for proteolysis of maternal serum proteins within the visceral yolk-sac epithelium. Near term, targeting of endocytosed protein to secondary lysosomes for proteolysis appears to be augmented; transcellular routing of maternal protein (e.g., IgG) for placental transport may be impeded. Thus significance of the observed changes in the fine structure of this placenta may relate to the mechanism(s) of action of maternal alcohol consumption on the acquisition of neonatal immunity, intrauterine growth retardation, and the production of congenital malformations.

Animals↗
PubMed1986

Changes in absorptive surfaces of rat visceral yolk sac with increasing gestational age.

The free surface of the endodermal epithelial lining of the rat visceral yolk sac was examined by scanning electron microscopy at three stages of pregnancy, viz., 12, 17 and 22 days (birth typically occurring on the 23rd day). Additionally, by ultrasonic vibration of tissues that had been subjected to prolonged osmium fixation, the epithelium was removed and such microdissected membranes similarly were examined. With increasing gestational age the free surface of the epithelium underwent a relative increase in absorptive area by three mechanisms: formation of increasingly complex villous projections of the visceral yolk sac as a whole, a doming of the individual epithelial cells, and an increase in length and number of microvilli for each such cell. The resultant increase in surface area, however, could not be correlated with the onset of receptor mediated endocytosis at the latest stage. The basement membrane underlying the lining epithelium of the yolk sac easily was revealed by ultrasonication of well-fixed tissues; it was most fragile at 12 days at which time the procedure apparently either removed the lamina lucida of the basal lamina, exposing a fibrillar component of the lamina densa, or removed the entire basal laminar component of the basement membrane, exposing an underlying reticular lamina. At 17 days the basement membrane at the cores of denuded villi showed the negative impressions of the epithelial cells that had been removed; and at 22 days, when the membrane is known to be permeable to protein transfer, it was smooth, featureless, and appeared most durable.

Animals↗
PubMed1985

Immunocytochemical localization of antibody during placental transmission of immunity in rats.

Autologous anti-horseradish peroxidase antibody has been localized in pregnant rats at various levels through placental membranes en passage to fetal circulation. The antibody was complexed in situ with the antigen and the resulting complex was made visible electron microscopically by immunohistochemical techniques. Visceral yolk-sac membranes from fetuses during the last half of gestation, viz. at 12, 17, and 22 days gestation, were so examined; differences were noted in the localization of cytochemical reaction product at increasing gestational ages. In yolk-sac endodermal epithelium at 12 days, the product was identified on receptor areas at the free surface of the epithelium, in a system of endocytosed clathrin-coated vesicles, or endosomes, within a closely related apical canalicular system, and stored in subapical vacuoles. Uptake and storage appeared markedly reduced in membranes taken at 17 days and was least apparent at 22 days (the day before term). Moreover, the product of antibody localization was not identified in the apical canaliculi at the two later stages. It is believed that most antibody had been hydrolyzed by these later stages. However, at the latest stage, reaction product also was identified in small vesicles in the basal cytoplasm of the endodermal epithelium and in the endothelium of vitelline (i.e., fetal) capillaries. These morphological results suggest that during the latter half of pregnancy antibody is absorbed; it is stored and hydrolyzed early on, and is transferred to fetal circulation only near term, a conclusion in close accord with what is known physiologically about prenatal transmission of immunity in this species.

Animals↗
PubMed1985

Age changes in density of endometrial stromal cells of the rat.

Stromal cells were counted in the endometrium of the rat during aging. Cell counts were made in the subepithelial, middle and deep regions of the endometrium in the left uterine horn of virgin Sprague-Dawley rats at 36 days of age and at 4, 10, and 20-24 months. In all regions of the endometrium the density of stromal cells decreased with aging. Decrease in cell numbers per unit area was greatest in the middle and deep endometrium. In 20 to 24-month-old rats, the mean number of cell profiles within 0.085 mm2 of the middle endometrium had decreased to less than one-third the number that was present within the same area in the 36-day animal. In the deep endometrium of these oldest rats, the mean number of cells had decreased to less than one-fourth. An age-associated decrease in density of stromal cells may contribute to alterations that have been observed in hormone-dependent uterine synthetic activities during aging.

Aging↗
PubMed1984

Changes in the fine structure of rat visceral yolk-sac placenta during prolonged pregnancy.

Visceral yolk-sac membranes were obtained surgically from viable rat fetuses which had been retained experimentally in utero in lactating animals for as long as 3 days beyond delivery of their littermates. They were examined with the electron microscope. The fine structure of the yolk-sac placental membrane (i.e., the tissues separating vitelline capillary lumina from the uterine cavity) remained unimpaired during the delay period. Progressive changes included a decrease in the height of the endodermal epithelium, but a thickening of the basement membrane underlying it by repeated replication of the subepithelial basal lamina and an increase in collagen fiber content in the reticular lamina. Transcytosis across the endothelium of the capillaries of the peripheral vitelline circulation remained unchanged throughout the delay period; endocytosis of materials, presumably maternal serum proteins, from the uterine cavity into the apices of the endodermal epithelium, however, decreased with time. At the oldest stage (26 days post-coitum) most endocytosed materials had been stored for hydrolysis in large subapical vacuoles which were identified as secondary lysosomes; and evidence of uptake from the uterine lumen was essentially absent. Accordingly, placental transport of protein by the visceral yolk sac of the rat can be regarded as a perinatal process. The action of an elaborately developed and well-preserved Golgi apparatus in both cellular mechanisms, viz., digestion of maternal proteins and protein transfer, was inferred.

Animals↗
PubMed1984

The response of the uterine surface to ovarian hormones in the aged rat.

By scanning electron microscopy uterine luminal epithelium of the rat was studied to determine whether aging alters ovarian hormone stimulated ultrastructural changes in that portion of the endometrial surface into which implantation takes place in the younger animal. Results show that in the aged rat this surface differentiates in response to ovarian hormones in a manner qualitatively similar to that which occurs in the young animal. Epithelial cells of ovariectomized rats, both young and aged, were polygonal in outline, flattened, or even somewhat concave, and had short microvilli. Following estrogen treatment cells of both groups were round or oval and bulged into the lumen. Cells of young rats were covered with long microvilli. Most cells of aged rats had microvilli of equal or greater length; a small number of epithelial cells had fewer and shorter microvilli. Cells of progesterone-treated young and aged animals both were covered with short microvilli and bore membrane protrusions. The protrusions varied in size, shape and numbers both within and between age groups. These findings suggest that differences in the surface ultrastructure of the aged uterus reflect age-related changes in hormone levels.

Aging↗
PubMed1979

Ultrastructural effects of estrogen replacement on postmenopausal endometrium.

Endometrial adenocarcinoma occurs almost exclusively in postmenopausal women, and excessive or unopposed estrogen stimulation is suspect as a causative factor in its pathogenesis. Furthermore, the incidence of endometrial adenocarcinoma has increased in women undergoing estrogen replacement therapy. In the present study, the cellular response of premenopausal and postmenopausal endometrium to estrogenic stimulation was compared with endometrial adenocarcinoma by the electron microscope. Tissues were obtained at hysterectomy, endometrial biopsy, or endometrial curettage and were processed routinely for light and electron microscopy. Ultrastructurally the endometrium from postmenopausal patients undergoing estrogen replacement therapy was similar to normal cyclic endometrium in the late proliferative phase. At least three features of the estrogen-treated postmenopausal tissue resembled those observed in adenocarcinoma of the endometrium: accumulation of lipid droplets, irregular nuclei, and perinuclear whorls of microfibrils.

Adenocarcinoma↗
PubMed1979

The fine structure of placental junctional zone cells during prolonged pregnancy in rats.

The electron microscope was used to examine the junctional zone of the chorioallantoic placentas of living rat young which had been experimentally retained in utero for as long as 4 days beyond delivery of their littermates. Junctional zone cells in such prolonged placentas were compared with corresponding cellular elements in term placentas. By the 1st day of the postterm period, placental glycogen cells in the junctional zone were depleted. Many trophoblast giant cells and trophospongial elements appeared fully viable throughout the entire 4-day period, however, Giant cells from placentas of prolonged pregnancy were indistinguishable from those in placentas at term. Both in term and in postterm placentas the trophospongial elements displayed a variation in the organization of the granular cisterns of endoplasmic reticulum within them. No variants appearing to prefigure involution were identified either in term or in prolonged placentas. However, more cells with vesiculate cisterns were seen in junctional zones from placentas which were retained beyond term. Intercellular relationships also were preserved both in term and in prolonged placentas, it is concluded that parturition is not dependent on their involution.

Animals↗
PubMed1979

An ultrastructural comparison of human endometrial adenocarcinoma with normal postmenopausal endometrium.

Although electron microscopy has been of limited value in detecting malignant neoplasms, some neoplasms do exhibit characteristic ultrastructural features. Intensive study of these features may offer insight into the etiology and activity of such tumors. In an attempt to characterize the ultrastructure of endometrial adenocarcinoma, tissue was examined with the electron microscope and compared with normal postmenopausal endometrium. Endometria from biopsy, hysterectomy, or curettage were processed routinely for light and electron microscopy. Several ultrastructural features of the adenocarcinoma were common both to previous descriptions of endometrium of the postovulatory phase and to the normal postmenopausal endometrium, described here, viz, atypical mitochondrial forms and cell surface modifications. Ribosomes were abundant in adenocarcinoma of the endometrium, normal postmenopausal endometrium, and normal cyclic endometrium in the preovulatory phase.

Adenocarcinoma↗
PubMed1976

The fine structure of the interhemal membrane of the rat chorioallantoic placenta during prolonged pregnancy.

In placentas from viable rat fetuses which surgically had been retained beyond term in lactating animals for as long as four days, the fine structure of much of the interhemal membrane was quite like that of full-term placentas. Moreover, contrary to what has been reported previously (Jollie, '64a), in retained placentas which were autopsied at term there were few changes in the four cytoplasmic layers of the membrane which could be interpreted as degenerative. With prolongation of the placenta beyond normal delivery the number of pericytes which were associated with the allantoic endothelium increased; the basal lamina separating the endothelium from trophoblast III progressively became more focally split; and the apposed plasma membranes between this latter layer and trophoblast II appeared to dissociate. Trophoblast II became regionally divided in its cytoplasmic organization, its more superficial zone becoming highly infolded and/or vacuolar. As a consequence, the intertrophoblastic space between layers I and II became more extensive and complex. Within this space, a flocculent material appeared; and there was ultrastructural evidence of massive pinocytosis from the space by trophoblast II. With increased prolongation of gestation, a variety of lysosome-like inclusions appeared within this layer of the membrane.

Allantois↗
PubMed1975

Fine structural observations on hemopoiesis in the chorioallantoic placenta of the marmoset.

Hemopoietic sinuses in the chorionic trabeculae of marmoset placenta were examined electron microscopically at several stages of pregnancy. Tissues were prepared both by standard technique and following injection of exogenous peroxidase into the maternal circulation prior to autopsy, and subsequent cytochemical localization of its reaction product in the fetal placenta. Aside from their dilated size and cellular content, the sinuses resembled the allantoic capillaries of the peripheral umbilical circulation in this species; and in early and midgestational placentas, sinusal lumina, differentiating elements in the erythroid line were present in placentas at all stages. Such cells appeared to arise both by a process of proliferation of undifferentiated progenitors from the sinusal lining and by mitosis of pre-existing erythroid cells. Only the latter process was observed in the mature placenta near term. Granulopoiesis was not observed at any stage; on the other hand, cells in the thromboid line were identified in placentas believed to be near midgestation; and large intrasinusal phagocytes were present in both midgestational and late placentas. In the latter, they were seen to have endocytosed peroxidase, and, by tenuous, dendriform processes, to be related anatomically to large numbers of erythroid cells. Early in gestation, the developing erythroid elements were closely related by areas of contact, both to each other and to the delimiting endothelium of the sinuses.

Allantois↗