Calcitropic gene expression suggests a role for the intraplacental yolk sac in maternal-fetal calcium exchange

2002 ◽  
Vol 282 (3) ◽  
pp. E721-E732 ◽  
Author(s):  
Christopher S. Kovacs ◽  
Linda L. Chafe ◽  
Mandy L. Woodland ◽  
Kirsten R. McDonald ◽  
Neva J. Fudge ◽  
...  
Keyword(s):  
Time Frame ◽  
Yolk Sac ◽  
Late Gestation ◽  
Calcium Sensing ◽  
Parathyroid Hormone Related Protein ◽  
Active Calcium ◽  
Calcium Exchange ◽  
Calbindin D ◽  
Pthrp Receptor

The expression of calcitropic genes and proteins was localized within murine placenta during late gestation (the time frame of active calcium transfer) with an analysis of several gene-deletion mouse models by immunohistochemistry and in situ hybridization. Parathyroid hormone-related protein (PTHrP), the PTH/PTHrP receptor, calcium receptor, calbindin-D9k, Ca2+-ATPase, and vitamin D receptor were all highly expressed in a localized structure of the murine placenta, the intraplacental yolk sac, compared with trophoblasts. In the PTHrP gene-deleted or Pthrp-null placenta in which placental calcium transfer is decreased, calbindin-D9k expression was downregulated in the intraplacental yolk sac but not in the trophoblasts. These observations indicated that the intraplacental yolk sac contains calcium transfer and calcium-sensing capability and that it is a probable route of maternal-fetal calcium exchange in the mouse.

scholarly journals A thin, deformable, high-performance supercapacitor implant that can be biodegraded and bioabsorbed within an animal body

2021 ◽  
Vol 7 (2) ◽  
pp. eabe3097
Author(s):  
Hongwei Sheng ◽  
Jingjing Zhou ◽  
Bo Li ◽  
Yuhang He ◽  
Xuetao Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Electronic Devices ◽  
Form Factors ◽  
Time Frame ◽  
Water Soluble ◽  
Two Dimensional ◽  
Medical Electronics ◽  
Thin Structure ◽  
Shed Light

It has been an outstanding challenge to achieve implantable energy modules that are mechanically soft (compatible with soft organs and tissues), have compact form factors, and are biodegradable (present for a desired time frame to power biodegradable, implantable medical electronics). Here, we present a fully biodegradable and bioabsorbable high-performance supercapacitor implant, which is lightweight and has a thin structure, mechanical flexibility, tunable degradation duration, and biocompatibility. The supercapacitor with a high areal capacitance (112.5 mF cm−2 at 1 mA cm−2) and energy density (15.64 μWh cm−2) uses two-dimensional, amorphous molybdenum oxide (MoOx) flakes as electrodes, which are grown in situ on water-soluble Mo foil using a green electrochemical strategy. Biodegradation behaviors and biocompatibility of the associated materials and the supercapacitor implant are systematically studied. Demonstrations of a supercapacitor implant that powers several electronic devices and that is completely degraded after implantation and absorbed in rat body shed light on its potential uses.

The activities of thiol proteases in the rat visceral yolk sac increase during late gestation

Placenta ◽  
1991 ◽  
Vol 12 (2) ◽  
pp. 143-151 ◽  
Author(s):  
John D. Grubb ◽  
Thomas R. Koszalk ◽  
Joseph J. Drabick ◽  
Robert M. Metrione
Keyword(s):  
Yolk Sac ◽  
Late Gestation ◽  
Visceral Yolk Sac ◽  
Thiol Proteases

scholarly journals Evolution and Cell Physiology. 1. Cell signaling is all of biology

2013 ◽  
Vol 305 (7) ◽  
pp. C682-C689 ◽  
Author(s):  
John S. Torday
Keyword(s):  
Adrenergic Receptor ◽  
Receptor Gene ◽  
Pressure Control ◽  
Cell Physiology ◽  
Gene Duplications ◽  
Radical Oxygen Species ◽  
Dna Mutations ◽  
Parathyroid Hormone Related Protein ◽  
Unicellular Organisms ◽  
Pthrp Receptor

I hypothesize that the First Principles of Physiology (FPPs) were co-opted during the vertebrate transition from water to land, beginning with the acquisition of cholesterol by eukaryotes, facilitating unicellular evolution over the course of the first 4.5 billion years of the Earth's history, in service to the reduction in intracellular entropy, far from equilibrium. That mechanism was perpetuated by the advent of cholesterol in the cell membrane of unicellular eukaryotes, ultimately giving rise to the metazoan homologs of the gut, lung, kidney, skin, bone, and brain. Parathyroid hormone-related protein (PTHrP), whose cognate receptor underwent a gene duplication during the transition from fish to amphibians, facilitated gas exchange for the water-to-land transition, since PTHrP is necessary for the formation of lung alveoli: deletion of the PTHrP gene in mice causes the offspring to die within a few minutes of birth due to the absence of alveoli. Moreover, PTHrP is central to the development and homeostasis of the kidney, skin, gut, bone, and brain. Therefore, duplication of the PTHrP receptor gene is predicted to have facilitated the molecular evolution of all the necessary traits for land habitation through a common cellular and molecular motif. Subsequent duplication of the β-adrenergic receptor gene permitted blood pressure control within the lung microvasculature, allowing further evolution of the lung by increasing its surface area. I propose that such gene duplications were the result of shear stress on the microvasculature, locally generating radical oxygen species that caused DNA mutations, giving rise to duplication of the PTHrP and β-adrenergic receptor genes. I propose that one can determine the FPPs by systematically tracing the molecular homologies between the lung, skin, kidney, gut, bone, and brain across development, phylogeny, and pathophysiology as a type of “reverse evolution.” By tracing such relationships back to unicellular organisms, one can use the underlying principles to predict homeostatic failure as disease, thereby also potentially forming the basis for maneuvers that can treat or even prevent such failure.

Changes in glucocorticoid receptor mRNA in the developing ovine pituitary and the effects of exogenous cortisol

1995 ◽  
Vol 144 (3) ◽  
pp. 483-490 ◽  
Author(s):  
S G Matthews ◽  
K Yang ◽  
J R G Challis
Keyword(s):  
Glucocorticoid Receptor ◽  
Late Gestation ◽  
Developmental Changes ◽  
Pars Intermedia ◽  
Pars Distalis ◽  
Short Term ◽  
Neonatal Life ◽  
Inferior Aspect ◽  
Glucocorticoid Receptor Mrna

Abstract Developmental changes in pituitary glucocorticoid receptor (GR) mRNA were examined during gestation and early neonatal life using in situ hybridization. Pituitaries were harvested from sheep fetuses at days 60–80, 100–120, 130–135, 140–142 and term, and from lambs of days 0–7 and 30–60, and adults. GR mRNA was present in the pars distalis by day 60, levels increased through gestation, and there was a redistribution of GR mRNA, resulting in a relatively greater abundance at the base of the pars distalis. At term, there was a significant (P<0·05 compared with the day 140–142 fetuses) elevation of GR mRNA, which was maintained in the newborn lamb, reaching highest levels at days 30–60 of neonatal life. GR mRNA was undetectable in the pars intermedia until day 120, but subsequently increased to high levels at term. Interestingly, the expression of GR mRNA in the pars intermedia dropped precipitously in the newborn (P<0·05 compared with term), though levels recovered in the older lambs and adults. The regional and cellular distribution of GR mRNA correlated closely with the presence of immuno-reactive GR (irGR) in the pituitary; the majority of irGR was present in the nuclei. Intrafetal infusion of cortisol (12 h; 5 μg/min) in late gestation (day 135) had no effect on GR mRNA expression in either the pars distalis or pars intermedia. These results indicated that, in the fetal pituitary, (1) the GR gene is expressed in both the pars distalis and pars intermedia, (2) levels of GR mRNA in the fetal pituitary correlated with the distribution of nuclear irGR, (3) GR mRNA is present at higher levels in the inferior aspect of the pars distalis, its abundance increases immediately prior to parturition and is maintained in the newborn, and (4) cortisol infusion for 12 h does not affect GR mRNA in either region of the pituitary, suggesting that, in the short term, glucocorticoids do not directly regulate GR synthesis. Journal of Endocrinology (1995) 144, 483–490

scholarly journals Urachal yolk sac tumor penetrating the bladder as a diagnostic challenge: a case report and review of the literature

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Vladimír Šámal ◽  
Tomáš Jirásek ◽  
Vít Paldus ◽  
Igor Richter ◽  
Ondřej Hes
Keyword(s):  
Case Report ◽  
Rare Case ◽  
Yolk Sac ◽  
Cell Tumor ◽  
Yolk Sac Tumor ◽  
Review Of The Literature ◽  
Diagnostic Challenge ◽  
Macroscopic Hematuria ◽  
Rare Case Report

Abstract Background Yolk sac tumor (YST) is a germ cell tumor. It is primarily located in the gonads but can also occur extragonadally (extragonadal yolk sac tumor - EGYST), most commonly in the pelvis, retroperitoneum or mediastinum. Only a few YSTs of the urachus have been described. Case report We present a rare case report of a 37-year-old male with episodes of macroscopic hematuria. The histological specimen obtained by transurethral resection showed a solid, and in some parts papillary infiltrative, high-grade tumor with numerous areas of marked nuclear atypia and clear invasion between the detrusor bundles. Glandular pattern has been observed in only minority of the tumor. Immunohistochemistry showed significant positivity for GPC3, SALL4 and cytokeratins AE1/AE3, while KRT7 and GATA3 were negative. We concluded that the biopsy findings were consistent with urothelial carcinoma with infrequent YST differentiation. In definitive surgical specimens we found a malignant epithelial, glandular and cystically arranged tumor of germinal appearance arising from urachus. The surrounding urothelium was free of invasive or in situ tumor changes. We reclassified the tumor as a urachal YST. Conclusion EGYST was suspected because glandular and hepatoid structures were found, but the presence of these structures should be verified by immunohistochemistry.

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