Fetal organs

Sartorius Type BP 61 balance used for recording fetal organ weights. 

It is in this context, that in 2009, the DART committee formed a Steering Team to work on a project titled Consensus List of Developmental Toxicants. The Steering Team published a report of their deliberations and defined developmental toxicant in terms of its concentration in vitro (27). Daston et al. (27) based the definitions of positive and negative developmental toxicants according to their exposure conditions. That is, compounds on the list could have an exposure concentration that is unequivocally positive and a concentration that is unequivocally negative. In addition, only permanent effects that alter fetal organization, particularly structural malformations, were considered developmental toxicity. For example, fetal weight decreases (which are commonly used endpoints in risk assessment) are not considered developmental toxicity for the purposes of this list. 

As well reviewed elsewhere [2], the control exerted by 5a-reduced steroids on erythropoiesis is best explained by transcriptional control of the erythropoietin gene. Certainly, such androgens are actively concentrated in the nuclear chromatin of bone marrow, both in vivo and in vitro. By contrast, the situation is entirely different with respect to 5/3-reduced steroids. In the embryonic and fetal organs of many animals, aetiocholanolone or 5/3-DHT regulate the appearance of a 5 cap-recognition protein, without which the translation of the mRNAs for haemoglobin E (embry-... 

Cocaine exposure in utero can affect various fetal organs. Gastrointestinal disorders, including ten cases of necrotizing enterocolitis (291), one of intestinal atresia, and one of spontaneous colonic perforation, have been reported (292). 

Published data were used directly or to estimate values for the maternal and fetal extracellular space, maternal plasma volume and flow expansion during pregnancy, and maternal and fetal organ volumes and plasma flow. 

The model was run with a single intravenous bolus dose of 1 mg/kg at various times during a 22-day rat gestation period and compared with previously published (different author) maternal and fetal organ concentrations. The model was also run with a daily dosing for 98 days, ending on Gd 20, to simulate a typical human dietary exposure pattern for a frequent consumer of methylmercury-contaminated food. 

Functional Development of the Fetus The fetal organs mature during the third trimester but not at the same rate. This section reviews the lung, liver, kidneys, and blood development of the fetus. 

Balabaeva L, Tabacova S, Kurchatova G. 1979. Correlation of carbon disulfide exposure levels with tissue levels and some biochemical indices in maternal and fetal organism. Proc Int Congr Occup Health 19th 1 489-495. 

Srivastava VK, Chauhan SS, Srivastava PK, et al. 1990. Placental transfer of metals of coal fly ash into various fetal organs of rat. Arch Toxicol 64 153-156. 

While the importance of APC and host vasculature levels in early embryonic kidney precursor tissue carmot be underestimated, the observed reduced immunogenicity may reflect progressive development of a complex array of ceU surface molecules and soluble factors that determine immune recognition in the fetal organ. 

Methyhnercury can concentrate in certain fetal organs, such as the brain. The target organs are the brain and the central nervous system. It can cause death, miscarriage, and deformed fetuses. Unlike inorganic mercury compounds, it can penetrate through the membrane barrier of the erythrocyte. 

These alterations induced by the teratogen may occKir in the intracellular compartment in the nucleus and cytoplasm, at the cell surface, in the extracellular matrix and/or at the level of the fetal environment fetal organism, placental or maternal interactions (97). 

In rats fed green tea extract and catechins during pregnancy, fetuses were found to have one-hundredth of the catechins found in maternal plasma (Chu et al. 2006). Catechins were identified in several different fetal organs. 

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