Hypothetical role of prostaglandins in the onset of preterm labor after fetal surgery
ABSTRACT Preterm labor is one of the most important factors limiting the advancement of fetal surgery programs. While prostaglandins (PGs) have long been indicated as the key factor in the initiation of labor in humans, there is significant evidence showing that the chorionic membrane acts as a powerful barrier between the decidua/myometrium and amniotic PGs during normal pregnancy. After either open or endoscopic fetal surgery the imperfect, non-hermetical closure of the chorion permits leakage of PGs from the amnionic sac, allowing them to reach the decidua and myometrium. The surgical wound in the chorionic barrier could be the major factor involved in preterm labor and delivery after human fetal surgery.
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ABSTRACT: A number of revolutionary spacecraft structures and control concepts are currently being developed, which when successfully implemented will dramatically change the way future space systems are designed and developed. Many of these concepts will offer new challenges to the designers of the spacecraft structures and control systems. Some of the concepts being explored are: (i) Ultralight Precision Deployable Systems. Revolutionary concepts for compact, lightweight, deployable precision reflectors based on recent breakthroughs in ultralight optical quality mirrors and precision mechanisms. (ii) Multifunctional Structures Satellite. Satellite bus design concept using multifunctional structures (MFS) that promise to reduce the bus weight by an order of magnitude as well as the fabrication, integration, and launch cost. (iii) Lightweight Flexible Solar Array Systems. To meet the ever-demanding space power requirements at low weight, ultra-lightweight solar array concepts using advances in smart materials, multifunctional structures, and thin film photovoltaics promise up to a factor of five improvement over current technology. (iv) Launch Vehicle Payload Isolation. Passive and active isolation of the payload from the launch environment providing innovative approaches for spacecraft design, integration, test and launch survivability. These revolutionary concepts are explored in the context of their impact on the future design of spacecraftAerospace Conference, 1998 IEEE; 04/1998
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ABSTRACT: Fetal cardiac intervention (FCI) has been performed at our center in selected fetuses with complex congenital heart disease since 2000. Most interventions are performed in fetuses with a ductus arteriosus (DA)-dependent circulation. Indomethacin promotes closure of the DA in newborns and in fetal life, a potentially life threatening complication in fetuses with ductus-dependent congenital heart disease. We reviewed our experience with FCI with a focus on the frequency, features, and clinical course of ductal constriction. Fetuses undergoing FCI receive comprehensive pre- and postoperative cardiac and cerebral ultrasound evaluation, approximately 24 hours before and after the procedure, including imaging of DA flow and Doppler assessment of the umbilical artery and vein, ductus venosus, and, since 2004, the middle cerebral artery. Among 113 fetuses that underwent FCI, 24 of which were older than 28 0/7 weeks gestation, 2 were found to have DA constriction due to indomethacin therapy within 24 hours of intervention. Both of these were 30-week fetuses with hypoplastic left heart syndrome and restrictive or intact atrial septum. The DA was stenotic by spectral and color Doppler, and middle cerebral and umbilical artery pulsatility indexes were depressed. After discontinuation of indomethacin, the Doppler indices improved or normalized. Close echocardiographic monitoring of fetal Doppler flow velocities is very important after fetal intervention and indomethacin treatment, as the consequences of DA constriction in a fetus with hypoplastic left heart syndrome are potentially lethal. Sonographic evaluation should include measurement of cerebral and umbilical arterial flow velocities as well as color and spectral Doppler interrogation of the DA.Fetal Diagnosis and Therapy 12/2009; 27(1):40-5. DOI:10.1159/000268290 · 2.30 Impact Factor
- Circulation 03/2010; 121(10):1256-63. DOI:10.1161/CIRCULATIONAHA.109.870246 · 14.95 Impact Factor