Placental Barrier (placental + barrier)

Distribution by Scientific Domains

Selected Abstracts

Placental barrier in acute myeloid leukaemia

Michael Decker
No abstract is available for this article. [source]

Maternal anesthesia via isoflurane or ether differentially affects pre-and postnatal behavior in rat offspring

April E. Ronca
Abstract Our understanding of prenatal behavior has been significantly advanced by techniques for direct observation and manipulation of unanesthetized, behaving rodent fetuses with intact umbilical connections to the mother. These techniques involve brief administration of an inhalant anesthesic, enabling spinal transection of the rat or mouse dam, after which procedures can continue with unanesthetized dams and fetuses. Because anesthetics administered to the mother can cross the placental barrier, it is possible that fetuses are anesthetized to varying degrees. We compared in perinatal rats the effects of prenatal maternal exposure to two inhalant anesthetics: ether and isoflurane. Fewer spontaneous fetal movements and first postpartum nipple attachments were observed following maternal exposure to ether as compared to isoflurane. Neonatal breathing frequencies and oxygenation did not account for group differences in nipple attachment. Our results provide evidence that the particular inhalant anesthetic employed in prenatal manipulation studies determines frequencies of perinatal behavior. 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 675,684, 2007. [source]

Placental transfer and pharmacokinetics of allopurinol in late pregnant sows and their fetuses

Xanthine oxidoreductase (XOR) is a key enzyme in the evolvement of reperfusion injury resulting from birth asphyxia, a common cause of decreased viability and perinatal mortality in newborn piglets under farm conditions. At present no standard pharmacological intervention strategy is available to reduce these adverse effects of birth asphyxia. In the present study we aimed to evaluate placental transfer of allopurinol, an inhibitor of XOR. For this purpose, fetal catheterization of the jugular vein was conducted in five late pregnant sows (one fetus per sow). At 24,48 h after surgery, sows received allopurinol (15 mg/kg body weight; i.v.) and pharmacokinetics of allopurinol and its active metabolite oxypurinol were measured in both late pregnant sows and fetuses. Maternal and fetal blood samples were collected during and after allopurinol administration. Maternal Cmax values averaged 41.90 ,g/mL (allopurinol) and 3.68 ,g/mL (oxypurinol). Allopurinol crossed the placental barrier as shown by the average fetal Cmax values of 5.05 ,g/mL at 1.47 h after allopurinol administration to the sow. In only one fetus low plasma oxypurinol concentrations were found. Incubations of subcellular hepatic fractions of sows and 24-h-old piglets confirmed that allopurinol could be metabolized into oxypurinol. In conclusion, we demonstrated that allopurinol can cross the placental barrier, a prerequisite for further studies evaluating the use of allopurinol as a neuroprotective agent to reduce the adverse effects following birth asphyxia in neonatal piglets. [source]

A variable number of tandem repeats polymorphism influences the transcriptional activity of the neonatal Fc receptor ,-chain promoter

IMMUNOLOGY, Issue 1 2006
Ulrich J. H. Sachs
Summary The neonatal Fc receptor, FcRn, plays a central role in immunoglobulin G (IgG) transport across placental barriers. Genetic variations of FcRn-dependent transport across the placenta may influence antibody-mediated pathologies of the fetus and the newborn. Sequencing analysis of 20 unrelated individuals demonstrated no missense mutation within the five exons of the FcRn gene. However, a variable number of tandem repeats (VNTR) region within the FcRn promoter was observed, consisting of five different alleles (VNTR1,VNTR5). Alleles with two (VNTR2) and three (VNTR3) repeats were found to be most common in Caucasians (75 and 920%, respectively). Real-time polymerase chain reaction revealed that monocytes from VNTR3 homozygous individuals express 166-fold more FcRn transcript than do monocytes from VNTR2/VNTR3 heterozygous individuals (P = 0002). In reporter plasmid assays, the VNTR3 allele supported the transcription of a reporter gene twice as effectively as did the VNTR2 allele (P = 0003). Finally, under acidic conditions, monocytes from VNTR3 homozygous individuals showed an increased binding to polyvalent human IgG when compared with monocytes from VNTR2/VNTR3 heterozygous individuals (P = 0021). These data indicate that a VNTR promoter polymorphism influences the expression of the FcRn receptor, leading to different IgG-binding capacities. [source]