Patient with Mosaic Turner Syndrome and a Derivative X Chromosome with a Variant Triple X Diagnosis in Fetus: A Case Report.

Although Turner syndrome is most often sporadic, multigenerational recurrence has been reported more often in the offspring of women with mosaic or variant forms of Turner syndrome. We present a case in which natural conception in a woman with identified 45,X/46,XX mosaicism resulted in a fetus with a gain of a derivative X chromosome. The unexpected fetal finding prompted further cytogenetic evaluation of the patient and subsequent identification of an additional cell line with the same derivative X chromosome, not observed in the initial study. To our knowledge, this is the first case in which further investigation of an abnormal noninvasive prenatal screen resulted in the identification of both maternal and fetal sex chromosome abnormality. We discuss the discordant finding, similar cases, and potential phenotype with respect to skewed X inactivation. We also highlight the use of multiple testing methodologies to characterize the serendipitous identification of a derivative X chromosome.

Twin pregnancies discordant for single umbilical artery.

OBJECTIVE: To evaluate the perinatal outcomes in twin pregnancies discordant for single umbilical artery (SUA). STUDY DESIGN: This was a retrospective cohort study. Our database was searched for all cases of twin gestation and SUA from 1997-2009. We reviewed all the maternal and neonatal records and placental pathology reports. The outcomes of the SUA fetuses were compared to that of their co-twins with a 3-vessel cord (3VC). Paired t test and chi2 tests were used for statistical analyses. RESULTS: We identified 29 cases of twin pregnancies discordant for SUA out of 60,989 ultrasound patients. There were no differences in the prevalence of coexisting anomalies (34% vs. 21%, p = 0.38) between the SUA fetus and the 3VC fetus. The SUA fetus was found to have significantly lower mean birth weight (1,784 +/- 765 g vs. 2,053 +/- 668 g, p = 0.001), 1-minute Apgar score (6.83 +/- 1.89 vs. 7.62 +/- 1.18, p = 0.037), and umbilical artery cord pH (7.27 +/- 0.06 vs. 7.31 +/- 0.07, p = 0.001). The SUA fetus was smaller 79% of the time (p < 0.0001). The SUA fetus achieved a significantly lower percentile (12.77% +/- 21.8 vs. 32.00% +/- 27.56, p = 0.002) when calculating the customized growth potential. CONCLUSION: The fetus affected by an SUA in a twin gestation has impaired fetal growth and neonatal outcomes when compared to its 3VC counterpart.

Hyaluronidase modifies the biomechanical properties of the rat cervix and shortens the duration of labor independent of myometrial contractility.

OBJECTIVE: To investigate the effect of intracervical hyaluronidase on the biomechanical properties of the cervix and on uterine contractility. STUDY DESIGN: Sprague-Dawley rats (n = 33, term day 22) were injected with hyaluronidase (100 IU) or saline solution on day 18 of gestation (n = 8-9/group). On day 21, labor was induced with mifepristone (8 mg/rat). Injection-to-delivery times were recorded. Biomechanical properties of the cervix were assessed using stretch-tension analysis. Myometrial contractility was investigated in response to hyaluronidase (0.2-200 IU/mL), oxytocin (10(-10)M to 10(-5)M), and potassium chloride (60 mM). RESULTS: Delivery times were shorter in the hyaluronidase group (P = .03). Cervices of the treated animals showed higher measures of elasticity and plasticity (P = .02 for both). Myometrial sensitivity to hyaluronidase, oxytocin, or potassium chloride was not affected by the cervical application of hyaluronidase (P > .05 for all). CONCLUSION: Cervical hyaluronidase treatment shortens labor and alters the biomechanical properties of the cervix, independent of the myometrium.

Pregnancy complicated by cyclic vomiting syndrome.

BACKGROUND: Cyclic vomiting syndrome is a condition that consists of recurrent episodes of vomiting occurring between periods of normal health, with no apparent organic cause of vomiting. We report the sentinel case of pregnancy complicated by preexisting cyclic vomiting syndrome. CASE: A primigravida presented at 8 weeks of gestation with a complaint of protracted vomiting. She had been diagnosed previously with cyclic vomiting syndrome. An extensive workup was performed, and she was admitted for therapy numerous times during her pregnancy. She underwent an indicated preterm delivery for fetal growth restriction, oligohydramnios, and nonreassuring fetal testing. The neonate was discharged to home in stable condition. CONCLUSION: Cyclic vomiting syndrome can complicate pregnancy, and the gravida with cyclic vomiting syndrome may be at risk for pregnancy complications. Increased surveillance may be warranted.

The effect of prepregnancy obesity and sFlt-1-induced preeclampsia-like syndrome on fetal programming of adult vascular function in a mouse model.

OBJECTIVE: The purpose of this study was to test the hypothesis that prepregnancy obesity and soluble fms-like tyrosine kinase-1 (sFlt-1)-induced preeclampsia lead to altered vascular function in the offspring later in life. STUDY DESIGN: CD-1 female mice were placed on a low-fat (LF) or high-fat (HF) diet before mating. On day 8 of pregnancy, the HF mice were injected with adenovirus that carried either sFlt-1 (HF sFlt-1) or murine immunoglobulin G2alpha Fc fragment (HF mFc). LF dams received saline solution. After being weaned, all offspring were placed on a standard diet. At 3 months of age, the carotid artery was isolated for in vitro vascular reactivity studies. RESULTS: Among male offspring, the response to phenylephrine was significantly lower in the HF sFlt-1 group. The response to serotonin in males and to thromboxane in females was lower in the HF sFlt-1 and HF mFc groups. In females, the HF sFlt-1 and LF groups displayed less relaxation to acetylcholine. The response to phenylephrine was significantly lower in females than males in the HF mFc and LF groups. The response to thromboxane was significantly lower in the HF sFlt-1 females, compared with males. CONCLUSION: Prepregnancy obesity and preeclampsia alter fetal programming of adult vascular function. The mechanism is complex and gender specific.

Validation of the prediction model for success of vaginal birth after cesarean delivery.

OBJECTIVE: To validate a previously developed vaginal birth after cesarean (VBAC) prediction model using a patient cohort different than that from which it was derived. METHODS: We performed a cohort study of all term pregnant women (January 2002-August 2007) with one prior low transverse cesarean delivery attempting a trial of labor. Variables used in the final prediction model (maternal age, prepregnancy body mass index, ethnicity, prior vaginal delivery, prior VBAC, and indication for prior cesarean delivery) were extracted from medical records and used to calculate an individual woman's predicted VBAC success rate. These rates at the level of the study population then were partitioned into deciles and compared with the actual VBAC rates. RESULTS: Of 545 women who fit the inclusion criteria, 502 had complete data available. A total of 262 (52.2%) had VBAC. The predicted probability of VBAC, as calculated by the regression equation, was significantly higher in those who had a successful trial of labor (median 78.4%, interquartile range 62.1-88.2) than in those who did not (median 59.7%, interquartile range 50.8-75.3, P<.001). The predictive model had an area under the receiver operating characteristic of 0.70 (95% confidence interval 0.65-0.74, P<.001), which was similar to that originally described. The actual VBAC rates did not differ from the predicted rates when the predicted chance of success was less than 50%. Above a 50% predicted success, the achieved success rates were consistently 10-20% lower. CONCLUSION: The published nomogram is predictive of VBAC success. It may help pregnant women contemplating a trial of labor reach a more informed decision. LEVEL OF EVIDENCE: II.

Timing of perioperative antibiotics for cesarean delivery: a metaanalysis.

OBJECTIVE: The purpose of this study was to summarize the available evidence on timing of perioperative antibiotics for cesarean delivery. STUDY DESIGN: We searched the literature for studies that compare prophylactic antibiotics for cesarean delivery that are given before the procedure vs at cord clamping. Only randomized controlled trials were included. RESULTS: Preoperative administration significantly reduced the risk of postpartum endometritis (relative risk [RR], 0.47; 95% CI, 0.26-0.85; P = .012) and total infectious morbidity (RR, 0.50; 95% CI, 0.33-0.78; P = .002). There was a trend toward lower risk of wound infection (RR, 0.60; 95% CI, 0.30-1.21; P = .15). Preoperative administration of antibiotics did not significantly affect suspected neonatal sepsis that requires a workup (RR, 1; 95% CI, 0.70-1.42), proven sepsis (RR, 0.93; 95% CI, 0.45-1.96), or neonatal intensive care unit admissions (RR, 1.07 95% CI, 0.51-2.24). There was no significant heterogeneity between the randomized controlled trials. CONCLUSION: There is strong evidence that antibiotic prophylaxis for cesarean delivery that is given before skin incision, rather than after cord clamping, decreases the incidence of postpartum endometritis and total infectious morbidities, without affecting neonatal outcomes.

Transient exposure to transforming growth factor beta 3 under serum-free conditions enhances the biomechanical and biochemical maturation of tissue-engineered cartilage.

A goal of cartilage tissue engineering is the production of cell-laden constructs possessing sufficient mechanical and biochemical features to enable native tissue function. This study details a systematic characterization of a serum-free (SF) culture methodology employing transient growth factor supplementation to promote robust maturation of tissue-engineered cartilage. Bovine chondrocyte agarose hydrogel constructs were cultured under free-swelling conditions in serum-containing or SF medium supplemented continuously or transiently with varying doses of transforming growth factor beta 3 (TGF-beta3). Constructs were harvested weekly or bi-weekly and assessed for mechanical and biochemical properties. Transient exposure (2 weeks) to low concentrations (2.5-5 ng/mL) of TGF-beta3 in chemically defined medium facilitated robust and highly reproducible construct maturation. Constructs receiving transient TGF-beta3 exposure achieved native tissue levels of compressive modulus (0.8 MPa) and proteoglycan content (6-7% of wet weight) after less than 2 months of in vitro culture. This maturation response was far superior to that observed after continuous growth factor supplementation or transient TGF-beta3 treatment in the presence of serum. These findings represent a significant advance in developing an ex vivo culture methodology to promote production of clinically relevant and mechanically competent tissue-engineered cartilage constructs for implantation to repair damaged articular surfaces.

Delivery complicated by postpartum hemorrhage and lower extremity compartment syndrome.

BACKGROUND: Extremity compartment syndrome is a rare surgical complication in which increased intracompartmental pressure threatens the viability of the muscular and nervous tissue. We report a case of a delivery complicated by postpartum hemorrhage and a lower extremity compartment syndrome. CASE: A multigravida in her late 20s was admitted for induction of labor at 41 weeks of gestation. She underwent a cesarean delivery for a nonreassuring fetal heart rate tracing. The delivery was complicated by severe postpartum hemorrhage due to uterine atony, resulting in a cesarean hysterectomy. The patient developed a lower extremity compartment syndrome and underwent an emergent anterior tibial fasciotomy. CONCLUSION: Extremity compartment syndrome is rarely encountered in obstetric care; however, there may be an association with severe postpartum hemorrhage.

Effects of Runx2 genetic engineering and in vitro maturation of tissue-engineered constructs on the repair of critical size bone defects.

Genetic and tissue engineering strategies are being pursued to address the clinical limitations of current bone grafting materials. Based on our previous work demonstrating that overexpression of the Runx2 osteoblastic transcription factor and in vitro construct maturation synergistically enhanced in vivo mineralization in an ectopic site (Byers et al., Tissue Eng 2004;10:1757-1766), we examined the effects of these two parameters on the repair of critical size bone defects. Primary rat bone marrow stromal cells transduced with Runx2 or control (no Runx2 insert) retroviral vector were seeded onto 3D fused deposition-modeled polycaprolactone scaffolds. Runx2-modified cells produced biologically-equivalent mineralized matrices at nearly 2-fold higher rates than control cells. Constructs cultured in vitro for 1 day (immature) or 21 days (mineralized) were subsequently implanted into critical size calvaria defects in syngeneic rats, and bone healing was analyzed by micro-CT and histomorphometry at 28 days. Runx2-modified and control constructs precultured for 1 day healed to a greater extent than defects receiving no implant. Cell-free scaffolds yielded equivalent levels of bone formation as constructs precultured for 1 day. Interestingly, defects treated with control cell-seeded constructs precultured for 21 days exhibited low bone formation compared to other construct treatments, and repair was comparable to empty defects. In contrast, Runx2-modified constructs precultured for 21 days contained twice as much bone as control constructs precultured for 21 days and equivalent levels of new bone as cell-free and 1 day precultured constructs. These results demonstrate interplay between Runx2 genetically-modified cells and in vitro construct maturation in bone healing responses.

The effect of applied compressive loading on tissue-engineered cartilage constructs cultured with TGF-beta3.

In this study, we report that the sequential application of physiologic deformational loading after culturing with the growth factor TGF-beta3 (for 2-3 weeks) yields significantly stiffer chondrocyte-seeded agarose constructs than cultures in which deformational loading was applied during the initial 2-3 week TGF-beta3 exposure period. Using this culture protocol, engineered constructs were found to reach Young's modulus and GAG levels similar to that of native (parent) articular cartilage after only 42 days of culture. The present study extends the work on the mechanical preconditioning of engineered cartilage constructs to include transient supplementation with TGF-beta3 in a clinically-relevant, chemically-defined, serum-free media formulation.

Severe hemolytic disease of the newborn due to anti-Cw.

BACKGROUND: Pregnancies complicated by Rh isoimmunization have decreased significantly since the widespread use of Rh immune globulin. Uncommon red blood cell antigens have therefore become more clinically evident. We report a case of anti-Cw immunization that resulted in severe fetal anemia that required multiple transfusions. CASE: A 28-year-old multigravida presented to our service at 18 weeks of gestation with her fourth pregnancy. Her pregnancy was complicated by anti-Cw isoimmunization that resulted in severe fetal anemia requiring in utero fetal blood transfusions. CONCLUSION: While previous reports recommend only postpartum surveillance when Cw isoimmunization is present, we report a case resulting in severe fetal anemia.

Ultrasound and MRI appearance and evolution of hydranencephaly in utero: a case report.

BACKGROUND: Hydranencephaly is the total or near-total destruction of the cerebral cortex and basal ganglia. The thalami and lower brain centers are typically preserved. This condition is usually preceded by occlusion of the internal carotid arteries, resulting in massive brain infarction. CASE: An 18-year-old woman, gravida 1, presented with a 1-day history of heavy vaginal bleeding at 23 weeks' gestation. Initial ultrasound revealed oligohydramnios and retroplacental lucency consistent with placental abruption. A follow-up level II ultrasound revealed abnormal intracerebral architecture. Subsequent ultrasounds and magnetic resonance imaging (MRI) revealed an evolving case of hydranencephaly. Postdelivery computed tomography verified the prenatal findings. CONCLUSION: Ultrasound and MRI are useful radiologic studies to confirm the diagnosis of hydranencephaly.

Runx2/Cbfa1-genetically engineered skeletal myoblasts mineralize collagen scaffolds in vitro.

Genetic engineering of progenitor and stem cells is an attractive approach to address cell sourcing limitations associated with tissue engineering applications. Bone tissue engineering represents a promising strategy to repair large bone defects, but has been limited in part by the availability of a sustained, mineralizing cell source. This study examined the in vitro mineralization potential of primary skeletal myoblasts genetically engineered to overexpress Runx2/Cbfa1, an osteoblastic transcriptional regulator essential to bone formation. These cells were viable at the periphery of 3D fibrous collagen scaffolds for 6 weeks of static culture. Exogenous Runx2 expression induced osteogenic differentiation and repressed myogenesis in these constructs relative to controls. Runx2-modified cells deposited significant amounts of mineralized matrix and hydroxyapatite, as determined by microcomputed tomography, histological analysis, and Fourier transform infrared spectroscopy, whereas scaffolds seeded with control cells exhibited no mineralized regions. Although mineralization by Runx2-engineered cells was confined to the periphery of the construct, colocalizing with cell viability, it was sufficient to increase the compressive modulus of constructs 30-fold relative to controls. This work demonstrates that Runx2 overexpression in skeletal myoblasts may address current obstacles of bone tissue engineering by providing a potent cell source for in vitro mineralization and construct maturation. Additionally, the use of genetic engineering methods to express downstream control factors and transcriptional regulators, in contrast to soluble signaling molecules, represents a robust strategy to enhance cellular activities for tissue engineering applications.

Runx2/Cbfa1 stimulates transdifferentiation of primary skeletal myoblasts into a mineralizing osteoblastic phenotype.

Runx2, a transcriptional activator downstream of bone morphogenetic protein (BMP) signaling, is essential to osteoblastic differentiation and bone formation and maintenance. BMPs activate complex signaling networks, utilizing numerous signaling molecules and transcription factors to induce expression of osteoblastic markers in mesenchymal cell types. However, the role of Runx2 in this process, particularly in an environment independent of the other regulatory elements modulated by BMPs, remains poorly understood. In the present study, we used retroviral gene delivery to examine the effects of sustained Runx2 expression in primary myoblasts. Runx2 inhibited myogenesis, as demonstrated by suppression of MyoD and myogenin mRNA levels and reduced myotube formation. Additionally, Runx2-stimulated osteogenesis including osteoblastic gene expression, alkaline phosphatase activity, and biological mineral deposition. Notably, these osteogenic markers were induced to significantly greater levels than those observed in BMP-2-treated controls. These results demonstrate that direct exogenous expression of the Runx2 transcription factor, only one of numerous downstream targets of BMP signaling, is sufficient to induce transdifferentiation of myogenic cells into a mineralizing osteogenic lineage. This work underscores the potency of Runx2 as a regulator of osteogenesis and cell differentiation and provides new insights into the plasticity of committed mesenchymal cells.

Exogenous Runx2 expression enhances in vitro osteoblastic differentiation and mineralization in primary bone marrow stromal cells.

Bone marrow stromal cells represent a promising cell source for cell-based therapeutic and bone tissue-engineering applications, but are restricted by a low frequency in healthy marrow, an age-related decrease in osteogenic capacity, and a propensity for dedifferentiation during in vitro expansion. To address these limitations, retroviral gene delivery was used to examine the effects of sustained and elevated expression of the Runx2 osteoblastic transcription factor on osteoblastic gene and protein expression and mineralization in primary rat bone marrow stromal cells. Runx2 overexpression upregulated several osteoblast-specific genes, including collagen type I and osteocalcin, and enhanced alkaline phosphatase activity and biological mineral deposition. Forced Runx2 expression in combination with dexamethasone increased matrix mineralization compared with exogenous Runx2 expression or dexamethasone treatment alone, whereas dexamethasone-free control cultures displayed minimal mineralization. These additive effects suggest complementary interactions between Runx2 and dexamethasone-responsive regulatory factors. Finally, Runx2 overexpression in stromal cell cultures undergoing considerable in vitro expansion resulted in higher matrix mineralization capacity compared with controls, which completely lost the ability to produce mineralized matrix even in the presence of dexamethasone. These findings provide a novel strategy for cell-based therapeutic applications requiring significant numbers of osteogenic cells to synthesize mineralized constructs for the treatment of large bone defects.

Synergy between genetic and tissue engineering: Runx2 overexpression and in vitro construct development enhance in vivo mineralization.

Tissue engineering has emerged as a promising strategy to generate bone-grafting substrates. These approaches, however, are limited by an insufficient supply of committed osteoprogenitor cells and dedifferentiation of osteogenic cells during in vitro culture. To address these limitations, we engineered bone marrow stromal cells to constitutively express the osteoblastic transcription factor Runx2/Cbfa1, using retroviral gene delivery. These Runx2-modified cells were integrated into three-dimensional polymeric scaffolds to create tissue-engineered constructs. Compared with control stromal cells, Runx2 overexpression significantly upregulated osteoblastic differentiation and mineralization in vitro and in vivo in an ectopic, nonosseous subcutaneous site. More importantly, in vitro construct development to create a mineralized template before implantation dramatically enhanced subsequent in vivo mineralized tissue formation, providing a novel templating tissue-engineering strategy to improve in vivo mineralization. Finally, Runx2 overexpression and in vitro construct development synergistically enhanced in vivo mineralization compared with in vitro construct development or genetic engineering alone. This work provides a novel integrated genetic and tissue-engineering strategy to create mineralized templates for generating robust bone-grafting material.

Cell-type-dependent up-regulation of in vitro mineralization after overexpression of the osteoblast-specific transcription factor Runx2/Cbfal.

Functional expression of the transcriptional activator Runx2/Cbfal is essential for osteoblastic differentiation and bone formation and maintenance. Forced expression of Runx2 in nonosteoblastic cells induces expression of osteoblast-specific genes, but the effects of Runx2 overexpression on in vitro matrix mineralization have not been determined. To examine whether exogenous Runx2 expression is sufficient to direct in vitro mineralization, we investigated sustained expression of Runx2 in nonosteoblastic and osteoblast-like cell lines using retroviral gene delivery. As expected, forced expression of Runx2 induced several osteoblast-specific genes in NIH3T3 and C3H10T1/2 fibroblasts and up-regulated expression in MC3T3-E1 immature osteoblast-like cells. However, Runx2 expression enhanced matrix mineralization in a cell-type-dependent manner. NIH3T3 and IMR-90 fibroblasts overexpressing Runx2 did not produce a mineralized matrix, indicating that forced expression of Runx2 in these nonosteogenic cell lines is not sufficient to direct in vitro mineralization. Consistent with the pluripotent nature of the cell line, a fraction (25%) of Runx2-expressing C3H10T1/2 fibroblast cultures produced mineralized nodules in a viral supernatant-dependent manner. Notably, bone sialoprotein (BSP) gene expression was detected at significantly higher levels in mineralizing Runx2-infected C3H10T1/2 cells compared with Runx2-expressing cultures which did not mineralize. Treatment of Runx2-infected C3H10T1/2 cultures with dexamethasone enhanced osteoblastic phenotype expression, inducing low levels of mineralization independent of viral supernatant. Finally, Runx2 overexpression in immature osteoblast-like MC3T3-E1 cells resulted in acceleration and robust up-regulation of matrix mineralization compared with controls. These results suggest that, although functional Runx2 is essential to multiple osteoblast-specific activities, in vitro matrix mineralization requires additional tissue-specific cofactors, which supplement Runx2 activity.