Distribution of osteonectin mRNA and protein during human embryonic and fetal development.

1992 ◽  
Vol 40 (2) ◽  
pp. 283-291 ◽  
Author(s):  
S Mundlos ◽  
B Schwahn ◽  
T Reichert ◽  
B Zabel
Keyword(s):  
Fetal Development ◽  
Mineralized Tissue ◽  
Temporal And Spatial Distribution ◽  
Embryonic And Fetal Development ◽  
Specific Distribution ◽  
Mineralized Tissues ◽  
Organ Specific ◽  
Mineralized Zone

We investigated the temporal and spatial distribution of osteonectin during human embryonic and fetal development, using in situ hybridization and immunohistochemistry. Osteonectin gene expression was generally found in cells exhibiting high rates of matrix production/proliferation. In mineralized tissue, a strong signal was obtained in osteoblasts, odontoblasts, and chondrocytes of the upper hypertrophic and proliferative zones. Chondrocytes of the mineralized zone showed no expression throughout the different stages of development. Strong osteonectin expression was found in odontoblasts of developing teeth. In addition, osteonectin mRNA and protein were detected in several non-mineralized tissues: steroid-producing cells of the adrenal gland and the gonads, kidney (glomeruli), lung (bronchi), skin, megacaryocytes, and large vessels. Histochemistry confirmed the results and detected extracellular osteonectin in bone and in the zone of mineralized cartilage only. The localization of osteonectin in bone, cartilage, and teeth is consistent with a role in the initiation of mineralization. However, the organ-specific distribution in non-mineralized tissues suggests an important multifunction role of this protein during human development.

scholarly journals C-type natriuretic peptide in reproduction, pregnancy and fetal development

2004 ◽  
Vol 180 (1) ◽  
pp. 17-22 ◽  
Author(s):  
T Walther ◽  
H Stepan
Keyword(s):  
Natriuretic Peptide ◽  
Fetal Development ◽  
De Novo ◽  
Biological Effects ◽  
Endocrine Function ◽  
Comprehensive Overview ◽  
Specific Expression ◽  
Embryonic And Fetal Development ◽  
Organ Specific ◽  
Reproductive Processes

C-type natriuretic peptide (CNP) belongs to the natriuretic peptide family that consists of three structurally related peptides with a 17-amino acid ring linked by a disulfide bond. In contrast to atrial and brain natriuretic peptides that are mainly cardiovascular hormones, CNP acts predominantly in an autocrine/paracrine fashion, is commonly considered to be an endothelial hormone with antimitogenic properties, and is characterized as a regulator of endochondral ossification. Its biological effects are mediated by an intracellular cGMP accumulation via specific membrane-bound guanylyl cyclase B (GC-B) activation. There is growing evidence that this peptide is also involved in various reproductive processes as well as in embryonic and fetal development. In rodents, CNP and its receptor are highly expressed in the uterus and ovaries with specific regulation during the estrous cycle. During pregnancy, CNP mRNA is detectable in mice embryos and shows an organ-specific expression in maternal reproductive tIssues with the highest concentration in the placenta. This could indicate a defined biological function of the CNP/GC-B/cGMP axis in gestation e.g. antagonizing vasoconstrictive peptides like angiotensin II. In humans, besides a postulated fetal de novo synthesis of CNP, both the peptide and its receptor are expressed in the placenta and myometrium with opposite regulation of CNP in pregnancies complicated by pre-eclampsia or intrauterine growth retardation. Since the maternal plasma levels do not reflect these alterations, one can conclude that this part of the natriuretic peptide system acts locally suggesting that CNP-stimulated cGMP release exhibits organ-specific effects. Importantly, CNP has also become a peptide with a distinct role in male reproductive processes, since endocrine function of the testis and the regulation of penile erection are regulated by the CNP/GC-B axis. This review gives a comprehensive overview of the multiple functions of CNP in reproduction and pregnancy as well as in embryonic and fetal development.

Diminished responsiveness of human platelets to platelet-activating factor during pregnancy

1990 ◽  
Vol 259 (3) ◽  
pp. H766-H771
Author(s):  
E. Kornecki ◽  
Y. H. Ehrlich
Keyword(s):  
Platelet Aggregation ◽  
Fetal Development ◽  
Platelet Activating Factor ◽  
Inflammatory Cells ◽  
Human Platelets ◽  
Maternal Circulation ◽  
Potent Inducer ◽  
Embryonic And Fetal Development ◽  
Circulating Levels

Platelet-activating factor (PAF; PAF-acether) is a phospholipid that is synthesized and released by a number of inflammatory cells and is a potent inducer of platelet aggregation and secretion. In the present study we examined the responsiveness of human platelets to various concentrations of PAF during pregnancy and postpregnancy. We found that in pregnant individuals the responses of washed gel-filtered platelets to PAF were either absent or greatly reduced during the 22nd-30th wk of pregnancy and returned to normal in the postpartum period. In contrast, the responses of platelets to various concentrations of ADP were not altered during pregnancy. We propose that during pregnancy circulating levels of PAF in the maternal circulation, possibly originating from the fetus, may desensitize maternal platelet receptors to PAF, resulting in a diminished or a complete lack of response of platelets, specifically to PAF. These findings may have important implications for our understanding of the role of PAF in hemostasis during pregnancy and in embryonic and fetal development.

scholarly journals Mechanical Properties of the Chick Embryo Spinal Cord

2007 ◽  
Author(s):  
Ragi A. I. Elias ◽  
Jason Maikos ◽  
David I. Shreiber
Keyword(s):  
Mechanical Properties ◽  
Spinal Cord ◽  
Fetal Development ◽  
Growth And Development ◽  
Axon Growth ◽  
Neural Precursor ◽  
Mechanical Environment ◽  
Embryonic And Fetal Development ◽  
Cord Injury

Determining the mechanical properties of the spinal cord are useful to identify its response to sub-injurious loading experienced during normal motion, to evaluate the biomechanics of spinal cord injury (SCI) [1], and to understand the role of the changing mechanical environment in growth and development. While an array of studies have focused on the mechanical properties of adult spinal cords, those properties may not be the same as pediatric spinal cords, which undergoes significant changes during development. Additionally, during embryonic and fetal development, axon growth and neural precursor differentiation into neurons are at their peak.

scholarly journals Uterine Cytokine Production During the Menstrual Cycle and Preimplantation Stages in Mice

1999 ◽  
Vol 7 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Irene Athanassakis ◽  
Vagia Farmakiotis ◽  
Lina Papadimitriou
Keyword(s):  
Menstrual Cycle ◽  
Fetal Development ◽  
Cytokine Production ◽  
Immunoperoxidase Staining ◽  
Female Reproduction ◽  
Gm Csf ◽  
The Third ◽  
Specific Distribution ◽  
Maternal Protection

Female reproduction is the only system subjected to well defined periodic changes. The final stage of the menstrual cycle in mammals is the maturation of the ovum and the preparation of the female organism to support fetal development fertilization. Once pregnancy occurs, both maternal and fetal sites emit regulatory signals to ensure embryo development and maternal protection against a graft versus host (GvH) reaction initiated by the semi-allogeneic fetus. We and others have previously shown that each day of fetal development in mice is characterized by different cytokine production, detected not only at the proximity of the feto-placental unit (decidua, uterus), but also in maternal lymphoid organs (spleen), as well as in the serum. In the present study, we concentrated on the menstrual cycle and the preimplantation stages of pregnancy and defined the levels of GM-CSF, IL-10, IL-6, and IL-3 in the murine uterus during anoestrus, proestrus, oestrus, and second and third day of gestation. We show by immunofluorescence and ELISA techniques that GM-CSF is maintained at high levels during anoestrus, proestus, oestrus, and the second day of pregnancy while dropping on the third day. IL-3 levels are found elevated during proestrus, second and third day of gestation, IL-6 increases essentially during proestrus, whereas the production of IL-10 was detected during oestrus and the early stages of pregnancy. Immunoperoxidase staining on frozen sections of uteri during the early gestational period localize GM-CSF and IL-3 production in the endometrium, IL-10 in the endometrium on the second day of pregnancy, and endometrium/myometrium on the third day. Low levels of IL-6 could be detected in the endometrium/epithelium on the second day and endometrium/myometrium on the third day of gestation. The role of IL-3, IL-10, and, to a lesser degree, IL-6 is fortified by the embryo itself, since these cytokines were found to be produced by blastocysts as well. These results demonstrate the existence of a specific distribution of lymphokines within the uterine tissue, the role of which is being discussed.

{10-12} Twinning Mechanism During In Situ Micro-Tensile Loading of Pure Mg: Role of Basal Slip and Twin-Twin Boundary Interaction

2020 ◽  
Author(s):  
Nicolò Maria della Ventura ◽  
Szilvia Kalácska ◽  
Daniele Casari ◽  
Thomas Edward James Edwards ◽  
Johann Michler ◽  
...  
Keyword(s):  
Twin Boundary ◽  
Basal Slip ◽  
Tensile Loading ◽  
Boundary Interaction

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

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