The Experts below are selected from a list of 1851 Experts worldwide ranked by ideXlab platform
Irene Cetin - One of the best experts on this subject based on the ideXlab platform.
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Amino Acid Interconversions in the Fetal-Placental Unit: The Animal Model and Human Studies In Vivo
Pediatric Research, 2001Co-Authors: Irene CetinAbstract:Fetal growth and development are dependent upon the adequate provision of oxygen and substrates from the maternal circulation. The need for amino acids is related to protein synthesis, interconversion to other substrates, and oxidation. Amino acids cross the placenta by active transport systems, and their concentrations in the fetus are higher than in the mother. In addition, most amino acids are extensively metabolized within the placenta, and, for some nonessential amino acids, placental synthesis has been demonstrated in chronically catheterized fetal lambs. Interorgan cycling between the fetal liver and placenta has been hypothesized for nonessential amino acids like glycine and serine. Amino acids are oxidized within the fetal tissues, particularly in liver and muscle, with differences between amino acids and in relation to metabolic state. In human pregnancies, maternal-fetal transfer rates have been investigated in vivo by stable isotope methodologies performed at fetal blood sampling. The transfer rate of nonessential amino acids like glycine is significantly lower than for essential amino acids like leucine, confirming glycine synthesis in the Fetoplacental Unit also in human pregnancies. Moreover, when a steady state model is applied, the fetal-maternal ratio for [1-^13C]leucine is significantly reduced in pregnancies associated with intrauterine growth restriction , reflecting a decrease in leucine placental transfer and/or an increase in protein catabolism in the Fetoplacental Unit. This reduction is proportional to the degree of severity of intrauterine growth restriction but is significant also in those intrauterine growth-restricted fetuses with normal oxygenation and acid-base status.
Ch V Rao - One of the best experts on this subject based on the ideXlab platform.
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gonadotropin receptors in human Fetoplacental Unit implications for hcg as an intracrine paracrine and endocrine regulator of human Fetoplacental function
Placenta, 1992Co-Authors: Z M Lei, Ch V RaoAbstract:Summary The presence of human chorionic gonadotropin (hCG) receptors in mid and term pregnancy human placenta, amnion, chorion, and decidua was investigated by light and electron microscope immunocytochemistry using the monoclonal antibody to rat luteal hCG/LH receptors. In mid pregnancy, the hCG receptors were present in placenta, amnion, chorion, and decidua. At term pregnancy, while receptors in fetal membranes and decidua continued to be detected, no receptors were detected in placental tissue unless the tissues were pretreated with neuraminidase. Syncytiotrophoblasts contained more receptors than cytotrophoblasts in placenta, and decidua contained more receptors than amnion and chorion at mid and term pregnancy. While the receptors in decidua and chorion increased, the receptors in amnion decreased from mid to term pregnancy. Immunogold electron microscopy revealed that hCG receptors are not only present in cell membranes but also in intracellular vesicles, nuclear membranes, and the perimeter of condensed chromatin. In summary our results, demonstrating the presence of hCG receptors in human Fetoplacental Unit, suggest that hCG may have intracrine, paracrine, and endocrine roles.
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The presence of gonadotropin receptors in nonpregnant human uterus, human placenta, fetal membranes, and decidua.
The Journal of Clinical Endocrinology & Metabolism, 1990Co-Authors: E. Reshef, Ch V Rao, Zhenmin Lei, Dwight D. Pridham, N. Chegini, Judith L. LuborskyAbstract:The possible presence of gonadotropin receptors in nonpregnant human uterus and human Fetoplacental Unit was investigated by light microscope immunocytochemistry using a monoclonal antibody to rat luteal hCG/LH receptors. The receptor antibody cross-reacted with human and bovine hCG/LH receptors and appears to be directed against the receptor rather than other proteins, including HLA class I antigens. Uterus and Fetoplacental Unit contained receptor antibody-binding sites, which indicates the presence of hCG/LH receptors. In the endometrium these receptors were present in glandular and luminal epithelial cells as well as in stromal cells. In the myometrium the receptors were detected in circular and elongated myometrial smooth muscle and vascular smooth muscle. Comparison of immunostaining intensities, which indicates the presence of different amounts of receptors, revealed that luminal and glandular epithelial cells contained more receptors than stromal cells. These cells, in turn, contained more recepto...
Nicole Picard-hagen - One of the best experts on this subject based on the ideXlab platform.
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Conjugation and deconjugation reactions within the Fetoplacental compartment in a sheep model: a key factor determining bisphenol A fetal exposure
Drug Metabolism and Disposition, 2015Co-Authors: Tanguy Corbel, Elisabeth Perdu, Véronique Gayrard, Sylvie Puel, Marlène Lacroix, Catherine Viguié, Pierre-louis Toutain, Daniel Zalko, Nicole Picard-hagenAbstract:The widespread human exposure to bisphenol A (BPA), an endocrine disruptor targeting developmental processes, underlines the need to better understand the mechanisms of fetal exposure. Animal studies have shown that at a late stage of pregnancy BPA is efficiently conjugated by the Fetoplacental Unit, mainly into BPA-glucuronide (BPA-G), which remains trapped within the Fetoplacental Unit. Fetal exposure to BPA-G might in turn contribute to in situ exposure to bioactive BPA, following its deconjugation into parent BPA at the level of fetal sensitive tissues. The objectives of our study were 1) to characterize the BPA glucurono- and sulfoconjugation capabilities of the ovine fetal liver at different developmental stages, 2) to compare hepatic conjugation activities in human and sheep, and 3) to evaluate the extent of BPA conjugation and deconjugation processes in placenta and fetal gonads. At an early stage of pregnancy, and despite functional sulfoconjugation activity, ovine fetuses expressed low hepatic BPA conjugation capabilities, suggesting that this stage of development represents a critical window in terms of BPA exposure. Conversely, the late ovine fetus expressed an efficient detoxification system that metabolized BPA into BPA-G. Hepatic glucuronidation activities were quantitatively similar in adult sheep and humans. In placenta, BPA conjugation and BPA-G deconjugation activities were relatively balanced, whereas BPA-G hydrolysis was systematically higher than BPA conjugation in gonads. The possible reactivation of BPA-G into BPA could contribute to an increased exposure of fetal sensitive tissues to bioactive BPA in situ.
R. M. Mitsoda - One of the best experts on this subject based on the ideXlab platform.
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Features of the Fetoplacental Unit functional state in pregnant women with Epstein-Barr virus infection
Zaporozhye State Medical University, 2016Co-Authors: Yu. A. Pekar, R. M. MitsodaAbstract:Epstein-Barr virus (EBV) high prevalence, variety of its pathways, effects on gestational process, clear criteria of EBV infection diagnostics in pregnant women lack indicated study problem actuality. Aim. To study basic ultrasonic and cardiotokohraphic indicators the Fetoplacental Unit functional state and hemodynamics in pregnant women with EBV infection. Methods and results. 106 pregnant women with EBV infection were included into the study. Basic utero-placental-fetal hemodynamics indicators were assessed. The next fetal ultrasound methods were used: fetometry, Doppler ultrasonography and placentography; cardiotocography, nonstress test and biophysical profile of the fetus. It was found that such hemodynamic disturbances as increased velocity of circulation can be diagnosed in pregnant women with EBV infection activation. This shows the tension of the compensatory reactions and the Fetoplacental insufficiency formation. Conclusion. The results suggest lack of effectiveness of conventional treatment and prevention and the need for their improvement in this group of pregnant wome
Tanguy Corbel - One of the best experts on this subject based on the ideXlab platform.
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Conjugation and deconjugation reactions within the Fetoplacental compartment in a sheep model: a key factor determining bisphenol A fetal exposure
Drug Metabolism and Disposition, 2015Co-Authors: Tanguy Corbel, Elisabeth Perdu, Véronique Gayrard, Sylvie Puel, Marlène Lacroix, Catherine Viguié, Pierre-louis Toutain, Daniel Zalko, Nicole Picard-hagenAbstract:The widespread human exposure to bisphenol A (BPA), an endocrine disruptor targeting developmental processes, underlines the need to better understand the mechanisms of fetal exposure. Animal studies have shown that at a late stage of pregnancy BPA is efficiently conjugated by the Fetoplacental Unit, mainly into BPA-glucuronide (BPA-G), which remains trapped within the Fetoplacental Unit. Fetal exposure to BPA-G might in turn contribute to in situ exposure to bioactive BPA, following its deconjugation into parent BPA at the level of fetal sensitive tissues. The objectives of our study were 1) to characterize the BPA glucurono- and sulfoconjugation capabilities of the ovine fetal liver at different developmental stages, 2) to compare hepatic conjugation activities in human and sheep, and 3) to evaluate the extent of BPA conjugation and deconjugation processes in placenta and fetal gonads. At an early stage of pregnancy, and despite functional sulfoconjugation activity, ovine fetuses expressed low hepatic BPA conjugation capabilities, suggesting that this stage of development represents a critical window in terms of BPA exposure. Conversely, the late ovine fetus expressed an efficient detoxification system that metabolized BPA into BPA-G. Hepatic glucuronidation activities were quantitatively similar in adult sheep and humans. In placenta, BPA conjugation and BPA-G deconjugation activities were relatively balanced, whereas BPA-G hydrolysis was systematically higher than BPA conjugation in gonads. The possible reactivation of BPA-G into BPA could contribute to an increased exposure of fetal sensitive tissues to bioactive BPA in situ.