The road (not) taken – Placental transfer and interspecies differences

Placenta ◽  
2021 ◽  
Vol 115 ◽  
pp. 70-77
Author(s):  
André Schmidt ◽  
Astrid Schmidt ◽  
Udo R. Markert
1997 ◽  
Vol 77 (3) ◽  
pp. 805-836 ◽  
Author(s):  
J. Stulc

There are great interspecies differences in placental structure as well as in permeability properties of the placenta. In all species, however, the placenta behaves like a low-permeability barrier containing specific mechanisms of transcellular transport for minerals and other substrates for fetal growth and metabolism. The minerals that are contained in plasma in low concentrations and that are mainly intracellular or sequestered in bones (K+, Mg2+, Ca2+, phosphate) are transported to the fetus actively. The transfer of the main extracellular ions, Na+ and Cl-, exhibit great interspecies differences. In the sheep, the transfer rates of Na+ and Cl- to the fetus are consistent with passive transfer mechanisms. In the rat, Na+ is transported to the fetus actively and the transfer of Cl- is facilitated by a carrier and/or a channel. Transfer of minerals to the fetus is controlled by a variety of mechanisms ranging from very simple ones depending on intrinsic properties of the transport systems to complex mechanisms of hormonal control. Water is presumed to move across the placenta passively. The transfer may be facilitated by the 28-kDa water channel-forming integral protein (CHIP28), which is expressed in the trophoblast syncytium.


2021 ◽  
Vol 12 ◽  
Author(s):  
Asmaa Beltagy ◽  
Azin Aghamajidi ◽  
Laura Trespidi ◽  
Wally Ossola ◽  
Pier Luigi Meroni

Females are generally more affected by autoimmune diseases, a fact that underlines the relationship with pregnancy and the safety of anti-rheumatic drugs in pregnancy and lactation. Biologic therapies are increasingly prescribed to treat and maintain remission in a significant number of systemic autoimmune rheumatic diseases. The experience with the use of biologics during gestation is extremely lacking because of the observational nature of the available studies and the difficulty in designing proper clinical trials in pregnancy. Among the studied biologics, more information was published on TNFα inhibitors and, in particular, on their potential passage through the placenta and impact on the fetus. Currently, a fragment of anti-TNFα monoclonal IgG, certolizumab pegol, is considered safe with almost no placental transfer. Subsequent observations are suggesting a comparable safety for the soluble TNFα receptor etanercept. Another biologic, eculizumab, the anti-C5a antibody used to treat complement-mediated microangiopathies, is also considered safe due to the unique engineered IgG2/4κ formulation that limits its passage through the placental barrier. Still, long-term data about children born to women treated with biologics in pregnancy are not attainable. Data on breastfeeding are currently available for several biologics. This article reviews the literature available about which drugs are considered safe during pregnancy and lactation, which are not, and on future prospects.


2019 ◽  
Vol 3 (5) ◽  
pp. 435-443 ◽  
Author(s):  
Addy Pross

Despite the considerable advances in molecular biology over the past several decades, the nature of the physical–chemical process by which inanimate matter become transformed into simplest life remains elusive. In this review, we describe recent advances in a relatively new area of chemistry, systems chemistry, which attempts to uncover the physical–chemical principles underlying that remarkable transformation. A significant development has been the discovery that within the space of chemical potentiality there exists a largely unexplored kinetic domain which could be termed dynamic kinetic chemistry. Our analysis suggests that all biological systems and associated sub-systems belong to this distinct domain, thereby facilitating the placement of biological systems within a coherent physical/chemical framework. That discovery offers new insights into the origin of life process, as well as opening the door toward the preparation of active materials able to self-heal, adapt to environmental changes, even communicate, mimicking what transpires routinely in the biological world. The road to simplest proto-life appears to be opening up.


ASHA Leader ◽  
2006 ◽  
Vol 11 (5) ◽  
pp. 14-17 ◽  
Author(s):  
Shelly S. Chabon ◽  
Ruth E. Cain

2009 ◽  
Vol 43 (9) ◽  
pp. 18-19
Author(s):  
MICHAEL S. JELLINEK
Keyword(s):  
The Road ◽  

2009 ◽  
Vol 2 (5) ◽  
pp. 1-17
Author(s):  
PATRICE WENDLING

1975 ◽  
Vol 20 (11) ◽  
pp. 905-906
Author(s):  
DALE L. JOHNSON
Keyword(s):  

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