Autologous Transplantation of Amniotic Fluid-Derived Mesenchymal Stem Cells into Sheep Fetuses.

Long-term engraftment and phenotype correction has been difficult to achieve in humans after in utero stem cell transplantation mainly because of allogeneic rejection. Autologous cells could be obtained during gestation from the amniotic fluid with minimal risk for the fetus and the mother. Using a sheep model, we explored the possibility of using amniotic fluid mesenchymal stem cells (AFMSCs) for autologous in utero stem cell/gene therapy.

Local over-expression of VEGF-DΔNΔC in the uterine arteries of pregnant sheep results in long-term changes in uterine artery contractility and angiogenesis.

Background: The normal development of the uteroplacental circulation in pregnancy depends on angiogenic and vasodilatory factors such as vascular endothelial growth factor (VEGF). Reduced uterine artery blood flow (UABF) is a common cause of fetal growth restriction; abnormalities in angiogenic factors are implicated. Previously we showed that adenovirus (Ad)-mediated VEGF-A165 expression in the pregnant sheep uterine artery (UtA) increased nitric oxide synthase (NOS) expression, altered vascular reactivity and increased UABF.

Monitoring for potential adverse effects of prenatal gene therapy: use of large animal models with relevance to human application.

Safety is an absolute prerequisite for introducing any new therapy, and the need to monitor the consequences of administration of both vector and transgene to the fetus is particularly important. The unique features of fetal development that make it an attractive target for gene therapy, such as its immature immune system and rapidly dividing populations of stem cells, also mean that small perturbations in pregnancy can have significant short- and long-term consequences. Certain features of the viral vectors used, the product of the delivered gene, and sometimes the invasive techniques necessary to deliver the construct to the fetus in utero have the potential to do harm.

Animal models for prenatal gene therapy: the sheep model.

Large animal experiments are vital in the field of prenatal gene therapy, to allow translation from small animals into man. Sheep provide many advantages for such experiments. They have been widely used in research into fetal physiology and pregnancy and the sheep fetus is a similar size to that in the human.

Effects of sildenafil in Nω-nitro-L-arginine methyl ester-induced intrauterine growth restriction in a rat model.

Objective: To assess the effect of sildenafil citrate in a rat model of Nω-nitro-l-arginine methyl ester (L-NAME)-induced intrauterine growth restriction (IUGR).

Study Design: An in vivo experimental study was conducted where 40 pregnant Sprague-Dawley rats were randomly assigned to receive either: (1) control, (2) L-NAME 50 mg/kg/d by gavage (days 14 to 19), (3) L-NAME and sildenafil 15 mg/kg/d by gavage, or (4) sildenafil (days 14 to 21). On day 21, a hysterotomy was performed and all fetuses (live and dead) were counted, examined, and weighed.

Organ targeted prenatal gene therapy--how far are we?

Prenatal gene therapy aims to deliver genes to cells and tissues early in prenatal life, allowing correction of a genetic defect, before long-term tissue damage has occurred. In contrast to postnatal gene therapy, prenatal application can target genes to a large population of dividing stem cells, and the smaller fetal size allows a higher vector-to-target cell ratio to be achieved. Early-gestation delivery may allow the development of immune tolerance to the transgenic protein which would facilitate postnatal repeat vector administration if needed.

Fetal muscle gene therapy/gene delivery in large animals.

Gene delivery to the fetal muscles is a potential strategy for the early treatment of muscular dystrophies. In utero muscle gene therapy can also be used to treat other genetic disorders such as hemophilia, where the missing clotting proteins may be secreted from the treated muscle. In the past few years, studies in small animal models have raised the hopes that a phenotypic cure can be obtained after fetal application of gene therapy.

Telemetric monitoring of fetal blood pressure and heart rate in the freely moving pregnant sheep: a feasibility study.

Remote telemetric monitoring of fetal haemodynamics in pregnant sheep would allow unrestricted animal movement, minimize suffering and distress, and improve animal welfare, while enhancing the quality of data collected. This may also be useful in clinical practice following fetal surgery. Using an open fetal surgical technique at approximately two-thirds of gestation, we implanted the catheter of a D70-PCTP haemodynamic telemetric device (Data Sciences International, Tilburg, The Netherlands) into the carotid artery of the fetal sheep (n = 4).

Autologous transplantation of amniotic fluid-derived mesenchymal stem cells into sheep fetuses.

Long-term engraftment and phenotype correction has been difficult to achieve in humans after in utero stem cell transplantation mainly because of allogeneic rejection. Autologous cells could be obtained during gestation from the amniotic fluid with minimal risk for the fetus and the mother. Using a sheep model, we explored the possibility of using amniotic fluid mesenchymal stem cells (AFMSCs) for autologous in utero stem cell/gene therapy.

Recombinant adeno-associated virus-mediated in utero gene transfer gives therapeutic transgene expression in the sheep.

Somatic in utero gene therapy aims to treat congenital diseases where pathology develops in perinatal life, thereby preventing permanent damage. The aim of this study was to determine whether delivery of self-complementary (sc) adeno-associated virus (AAV) vector in utero would provide therapeutic long-term transgene expression in a large animal model. We performed ultrasound-guided intraperitoneal injection of scAAV2/8-LP1-human Factor IX (hFIX)co (1 × 10(12) vector genomes/kg) in early (n = 4) or late (n = 2) gestation fetal sheep.

Ultrasonographic development of the fetal sheep stomach and evaluation of early gestation ultrasound-guided in utero intragastric injection.

Objective: Safely targeting the fetal gastrointestinal tract during early gestation is essential to develop effective prenatal gene therapy for gastrointestinal diseases. In this study, we aimed to characterize the development of the fetal sheep stomach sonographically and to determine the optimum gestational age, as well as the shortterm morbidity and mortality of early-gestation ultrasound-guided intragastric injection.

Materials And Methods: In experiments investigating ultrasound-guided prenatal gene therapy, we studied the size and development of the stomach of 185 sheep fetuses (33-144 days' gestational age [GA]; term is 145 days).

Bilateral neck cysts as an isolated sonographic finding in the antenatal detection of fetal aneuploidy: a case report.

Isolated fetal lateral neck cysts can represent a cystic hygroma or a developmental remnant cyst. In the absence of an increased nuchal translucency or associated malformations the risk of aneuploidy has been considered negligible. Still, dysmorphology in aneuploid fetuses might not be evident except at a later stage.

Dichorionic triamniotic triplet pregnancy complicated by acardius acormus.

This report describes an acardiac fetus of the acormus phenotype in a triplet pregnancy. The diagnosis was confirmed at 15 weeks. In the absence of signs of heart failure in the co-fetus the pregnancy was managed conservatively.

Doppler ultrasonography for the noninvasive measurement of uterine artery volume blood flow through gestation in the pregnant sheep.

Accurate noninvasive quantification of volume blood flow in the uterine arteries (UtAs) would have clinical and research benefits. We evaluated the correlation and agreement between uterine artery volume blood flow (UtABF) as calculated (cUtABF) from color/pulsed-wave Doppler acquisitions and that measured (mUtABF) by bilateral perivascular transit-time flow probes in 6 pregnant sheep at 2 gestational ages. Out of 22 Doppler acquisitions, 19 were successful.

Successful outcome after prenatal treatment of a cardiac diverticulum with massive pericardial effusion.

Congenital ventricular cardiac diverticula are rare. They may occur prenatally in association with a pericardial effusion which, if large enough, can compromise fetal circulatory and lung development. Parental counseling is difficult because some cases resolve in the second trimester and others progress to worsening hydrops and intrauterine death.

Lateral distribution of endometriomas as a function of age.

The lateral asymmetry of ovarian endometriomas, with a left-sided predilection, seems to disappear with advancing age. This asymmetry does not seem to persist in women >35 years of age.

Polypropylene midurethral tapes do not have similar biologic and biomechanical performance in the rat.

Objectives: To evaluate the biomechanical properties and histologic changes of different commercially available polypropylene midurethral tapes (MUTs) after implantation in the rat.

Methods: Pieces of Advantage, intravaginal slingplasty (IVS), suprapubic arch sling (SPARC), and tension-free vaginal tape (TVT) were implanted over the rectus fascia of rats, with six rats serving as controls. On retrieval 24 wk later, the degree of adherence and sample measurements were recorded.