A modelling approach to explore the critical environmental parameters influencing the growth and establishment of the invasive seaweed Undaria pinnatifida in Europe

A key factor to determine the expansion dynamics and future distribution of non-native species is their physiological response to abiotic factors and their changes over time. For this study we developed a spatially explicit, agent-based model of population growth to represent the complex population dynamics of invasive marine macroalgae with heteromorphic biphasic life cycles. The model framework represents this complex life cycle by treating the individual developmental stages (gametophytes/sporophytes) as autonomous agents with unique behaviour/growth parameters. It was parameterised to represent a well-documented invasive algal species, the Asian kelp Undaria pinnatifida, and validated against field results from an in situ population in Brittany, France, showing good quantitative agreement in terms of seasonal changes in abundance/recruitment and growth dynamics. It was then used to explore how local environmental parameters (light availability, temperature and day length) affect the population dynamics of the individual developmental stages and the overall population growth. This type of modelling approach represents a promising tool for understanding the population dynamics of macroalgae from the bottom-up in terms of the individual interactions between the independent life history stages (both microscopic and macroscopic). It can be used to trace back the behaviour of the population as a whole to the underlying physiological and environmental processes impacting each developmental stage and give insights into the roles these play in invasion success.

Hypoplastic left heart syndrome and the nutmeg lung pattern in utero: a cause and effect relationship or prognostic indicator?

BACKGROUND

Hypoplastic left heart syndrome (HLHS) is the third most common cause of critical congenital heart disease in newborns, and one of the most challenging forms to treat. Secondary pulmonary lymphangiectasia has been recognized in association with HLHS, an appearance described on fetal MRI as the "nutmeg lung."

OBJECTIVE

To investigate the association of fetal nutmeg lung with HLHS survival.

MATERIALS AND METHODS

A retrospective search of the fetal MRI database was performed. The nutmeg lung pattern was defined as T2 heterogeneous signal with tubular structures radiating peripherally from the hila. Postnatal echocardiograms and charts were reviewed.

RESULTS

Forty-four fetal MR studies met inclusion criteria, of which 4 patients (9%) had the nutmeg lung pattern and 3 of whom also had restrictive lesions. Mortality in this nutmeg lung group was 100% by 5 months of age. Of the 40 patients without nutmeg lung, mortality/orthotopic heart transplant (OHT) was 35%. Of these 40 patients without nutmeg lung, 5 had restriction on echo, 3 of whom died/had OHT before 5 months of age (60% of patients with restriction and non-nutmeg lung). There was a significantly higher incidence of restrictive lesions (P = 0.02) and mortality/OHT (P = 0.02) in patients with nutmeg lung compared to those without.

CONCLUSION

The nutmeg lung MR appearance in HLHS fetuses is associated with increased mortality/OHT (100% in the first 5 months of life compared to 35% with HLHS alone). Not all patients with restrictive lesions develop nutmeg lung, and outcome is not as poor when restriction is present in isolation. Dedicated evaluation for nutmeg lung pattern on fetal MR studies may be useful to guide prognostication and aid clinicians in counseling parents of fetuses with HLHS.

Effect of single and multiple courses of maternal betamethasone on prenatal congenital lung lesion growth and fetal survival

PURPOSE

Administration of maternal betamethasone (BMZ) is a therapeutic option for fetuses with large microcystic congenital lung lesions at risk for, or causing, hydrops. Not all fetuses respond to a single course of BMZ. We review our experience with the use of single and multiple courses of maternal BMZ for the management of these patients.

METHODS

A retrospective review of fetuses with congenital lung lesions managed with maternal BMZ from 2003 to 2014 was performed.

RESULTS

Forty-three patients were managed with prenatal steroids (28 single course, 15 multiple courses). Single course recipients demonstrated a reduction in lesion size and resolution of hydrops in 82% and 88% of patients respectively compared to 47% and 56% in recipients of multiple steroid courses. Survival of multiple course patients (86%) was comparable to that of single course patients (93%) and improved compared to non-treated historical controls. Multiple course recipients demonstrated an increased need for open fetal surgery and postnatal surgery at a younger age.

CONCLUSION

Fetuses who fail to respond to a single course of BMZ may benefit, as indicated by hydrops resolution and improved survival, from additional courses. However, failure to respond is indicative of a lesion which may require fetal or immediate neonatal resection.

Prenatal surgery for myelomeningocele and the need for cerebrospinal fluid shunt placement

OBJECT

The Management of Myelomeningocele Study (MOMS) was a multicenter randomized trial comparing the safety and efficacy of prenatal and postnatal closure of myelomeningocele. The trial was stopped early because of the demonstrated efficacy of prenatal surgery, and outcomes on 158 of 183 pregnancies were reported. Here, the authors update the 1-year outcomes for the complete trial, analyze the primary and related outcomes, and evaluate whether specific prerandomization risk factors are associated with prenatal surgery benefit.

METHODS

The primary outcome was a composite of fetal loss or any of the following: infant death, CSF shunt placement, or meeting the prespecified criteria for shunt placement. Primary outcome, actual shunt placement, and shunt revision rates for prenatal versus postnatal repair were compared. The shunt criteria were reassessed to determine which were most concordant with practice, and a new composite outcome was created from the primary outcome by replacing the original criteria for CSF shunt placement with the revised criteria. The authors used logistic regression to estimate whether there were interactions between the type of surgery and known prenatal risk factors (lesion level, gestational age, degree of hindbrain herniation, and ventricle size) for shunt placement, and to determine which factors were associated with shunting among those infants who underwent prenatal surgery.

RESULTS

Ninety-one women were randomized to prenatal surgery and 92 to postnatal repair. The primary outcome occurred in 73% of infants in the prenatal surgery group and in 98% in the postnatal group (p < 0.0001). Actual rates of shunt placement were only 44% and 84% in the 2 groups, respectively (p < 0.0001). The authors revised the most commonly met criterion to require overt clinical signs of increased intracranial pressure, defined as split sutures, bulging fontanelle, or sunsetting eyes, in addition to increasing head circumference or hydrocephalus. Using these modified criteria, only 3 patients in each group met criteria but did not receive a shunt. For the revised composite outcome, there was a difference between the prenatal and postnatal surgery groups: 49.5% versus 87.0% (p < 0.0001). There was also a significant reduction in the number of children who had a shunt placed and then required a revision by 1 year of age in the prenatal group (15.4% vs 40.2%, relative risk 0.38 [95% CI 0.22-0.66]). In the prenatal surgery group, 20% of those with ventricle size < 10 mm at initial screening, 45.2% with ventricle size of 10 up to 15 mm, and 79.0% with ventricle size ≥ 15 mm received a shunt, whereas in the postnatal group, 79.4%, 86.0%, and 87.5%, respectively, received a shunt (p = 0.02). Lesion level and degree of hindbrain herniation appeared to have no effect on the eventual need for shunting (p = 0.19 and p = 0.13, respectively). Similar results were obtained for the revised outcome.

CONCLUSIONS

Larger ventricles at initial screening are associated with an increased need for shunting among those undergoing fetal surgery for myelomeningocele. During prenatal counseling, care should be exercised in recommending prenatal surgery when the ventricles are 15 mm or larger because prenatal surgery does not appear to improve outcome in this group. The revised criteria may be useful as guidelines for treating hydrocephalus in this group.

Axillary lymphatic malformations: Prenatal evaluation and postnatal outcomes

BACKGROUND/PURPOSE

The purpose of this study is to describe the prenatal findings and postnatal outcomes of fetuses with axillary lymphatic malformations.

METHODS

Retrospective chart review of fetuses with the prenatal diagnosis of isolated axillary lymphatic malformation detected between 2009 and 2013.

RESULTS

There were 8 fetuses diagnosed with isolated axillary lymphatic malformation. Median gestational age at diagnosis was 20.5 (19-28) weeks. All fetuses were evaluated by serial ultrasound and ultrafast fetal MRI. Two pregnancies were electively terminated. All continued pregnancies reached term, and all fetuses were delivered by cesarean section. None of the fetuses developed polyhydramnios or hydrops fetalis. Only one patient had an associated malformation (coarctation of the aorta). All patients were evaluated postnatally by MRI. Treatment included sclerotherapy only (1), sclerotherapy followed by surgical resection (1), surgical resection only (3), and observation (1). The median postnatal hospital stay was 8 (6-15) days. Three cases recurred after the initial treatment, two after surgery and one after sclerotherapy. On a median follow up of 2.1 years, all patients have some degree of visible residual disease. There were no deaths.

CONCLUSIONS

Prenatal diagnosis of axillary lymphatic malformation is increasing with improved technology. Axillary lymphatic malformations are usually isolated developmental anomalies that do not affect fetal health. Postnatal management options include surgery, sclerotherapy, and observation. Recurrences and residual disease after all types of treatment are frequent. This should be communicated to the parents at the time of prenatal counseling.

Inclusion of Palmaria palmata (red seaweed) in Atlantic salmon diets: effects on the quality, shelf-life parameters and sensory properties of fresh and cooked salmon fillets

BACKGROUND

The use of Palmaria palmata (PP) as a natural ingredient in farmed Atlantic salmon diets was investigated. The effect of salmon diet supplementation with P. palmata (0, 5, 10 and 15%) or synthetic astaxanthin (positive control, PC) for 16 weeks pre-slaughter on quality indices of fresh salmon fillets was examined. The susceptibility of salmon fillets/homogenates to oxidative stress conditions was also measured.

RESULTS

In salmon fillets stored in modified atmosphere packs (60% N2 /40% CO2 ) for up to 15 days at 4 °C, P. palmata increased surface -a* (greenness) and b* (yellowness) values in a dose-dependent manner, resulting in a final yellow/orange flesh colour. In general, the dietary addition of P. palmata had no effect on pH, lipid oxidation (fresh, cooked and fillet homogenates) and microbiological status. 'Eating quality' sensory descriptors (texture, odour and oxidation flavour) in cooked salmon fillets were not influenced by dietary P. palmata. Salmon fed 5% PP showed increased overall acceptability compared with those fed PC and 0% PP.

CONCLUSION

Dietary P. palmata was ineffective at providing red coloration in salmon fillets, but pigment deposition enhanced fillets with a yellow/orange colour. Carotenoids from P. palmata may prove to be a natural pigment alternative to canthaxanthin in salmon feeds.

Measuring acoustic habitats

1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies.

Spatial transferability of habitat suitability models of Nephrops norvegicus among fished areas in the Northeast Atlantic: sufficiently stable for marine resource conservation?

Knowledge of the spatial distribution and habitat associations of species in relation to the environment is essential for their management and conservation. Habitat suitability models are useful in quantifying species-environment relationships and predicting species distribution patterns. Little is known, however, about the stability and performance of habitat suitability models when projected into new areas (spatial transferability) and how this can inform resource management. The aims of this study were to model habitat suitability of Norway lobster (Nephrops norvegicus) in five fished areas of the Northeast Atlantic (Aran ground, Irish Sea, Celtic Sea, Scotland Inshore and Fladen ground), and to test for spatial transferability of habitat models among multiple regions. Nephrops burrow density was modelled using generalised additive models (GAMs) with predictors selected from four environmental variables (depth, slope, sediment and rugosity). Models were evaluated and tested for spatial transferability among areas. The optimum models (lowest AICc) for different areas always included depth and sediment as predictors. Burrow densities were generally greater at depth and in finer sediments, but relationships for individual areas were sometimes more complex. Aside from an inclusion of depth and sediment, the optimum models differed between fished areas. When it came to tests of spatial transferability, however, most of the models were able to predict Nephrops density in other areas. Furthermore, transferability was not dependent on use of the optimum models since competing models were also able to achieve a similar level of transferability to new areas. A degree of decoupling between model 'fitting' performance and spatial transferability supports the use of simpler models when extrapolating habitat suitability maps to different areas. Differences in the form and performance of models from different areas may supply further information on the processes shaping species' distributions. Spatial transferability of habitat models can be used to support fishery management when the information is scarce but caution needs to be applied when making inference and a multi-area transferability analysis is preferable to bilateral comparisons between areas.

Thoracoamniotic shunts for the management of fetal lung lesions and pleural effusions: a single-institution review and predictors of survival in 75 cases

PURPOSE

Hydrops and pulmonary hypoplasia are associated with significant morbidity and mortality in the setting of a congenital lung lesion or pleural effusion (PE). We reviewed our experience using in utero thoracoamniotic shunts (TA) to manage fetuses with these diagnoses.

METHODS

A retrospective review of fetuses diagnosed with a congenital lung lesion or pleural effusion who underwent TA shunt placement from 1998-2013 was performed.

RESULTS

Ninety-seven shunts were placed in 75 fetuses. Average gestational age (±SD) at shunt placement and birth was 25±3 and 34±5 weeks. Shunt placement resulted in a 55±21% decrease in macrocystic lung lesion volume and complete or partial drainage of the PE in 29% and 71% of fetuses. 69% of fetuses presented with hydrops, which resolved following shunt placement in 83%. Survival was 68%, which correlated with GA at birth, % reduction in lesion size, unilateral pleural effusions, and hydrops resolution. Surviving infants had prolonged NICU courses and often required either surgical resection or tube thoracostomy in the perinatal period.

CONCLUSION

TA shunts provide a therapeutic option for select fetuses with large macrocystic lung lesions or PEs at risk for hydrops and/or pulmonary hypoplasia. Survival following shunting depends on GA at birth, reduction in mass size, and hydrops resolution.

Ex utero intrapartum treatment (EXIT) in the management of cervical lymphatic malformation

PURPOSE

The purpose of this study was to review the outcomes and technical details of EXIT procedures performed in fetuses with large cervical lymphatic malformations.

METHODS

A retrospective chart review of fetuses with a prenatal diagnosis of cervical lymphatic malformation evaluated at our center between 1995 and 2013 was performed.

RESULTS

We evaluated a total of 112 fetuses with a prenatal diagnosis of cervical lymphatic malformation. Thirteen of the 112 fetuses (11%) were delivered by an EXIT procedure. Criteria to deliver by EXIT were: 1) deviation/compression/obstruction of the airway, and 2) involvement of the floor of the mouth. Two fetuses developed hydrops. Five fetuses developed polyhydramnios. Eleven EXITs were performed electively at term (n=7; 37-38 weeks) or late pre-term (n=4; 34-36/6 weeks), whereas two patients underwent emergency EXIT at 33 and 38 weeks, respectively. The airway was accessed successfully in 12 of 13 cases. Laryngoscopy only was sufficient in 7, rigid bronchoscopy was required in 4, and 1 required a tracheostomy. In one case with a massive lymphatic malformation of the face, neck, and airway, a tracheostomy was not attempted, and the fetus expired. Four patients had invasion of the larynx by the lymphatic malformation. Five patients required a tracheostomy later. Median time from fetal exposure to intubation was 8 (2-29) min. Median total EXIT time was 105.5 (67-142) min. Median maternal blood loss was 800 (300-1000) ml. Median maternal hospital stay was 4 (3-6) days.

CONCLUSION

The EXIT procedure allows controlled airway access in fetuses with cervical lymphatic malformations and evidence of airway impairment on prenatal images.

Fetal Myelomeningocele Repair: The Post-MOMS Experience at the Children's Hospital of Philadelphia

Background: Fetal myelomeningocele (fMMC) repair has become accepted as a standard of care option in selected circumstances. We reviewed our outcomes for fMMC repair from referral and evaluation through surgery, delivery and neonatal discharge. Material and Methods: All patients referred for potential fMMC repair were reviewed from January 1, 2011 through March 7, 2014. Maternal and neonatal data were collected on the 100 patients who underwent surgery. Results: 29% of those evaluated met the criteria and underwent fMMC repair (100 cases). The average gestational age was 21.9 weeks at evaluation and 23.4 weeks at fMMC repair. Complications included membrane separation (22.9%), preterm premature rupture of membranes (32.3%) and preterm labor (37.5%). Average gestational age at delivery was 34.3 weeks and 54.2% delivered at ≥35 weeks. The perinatal loss rate was 6.1% (2 intrauterine fetal demises and 4 neonatal demises); 90.8% of women delivered at the Children's Hospital of Philadelphia and 3.4% received transfusions. With regard to the neonates, 2 received ventriculoperitoneal shunts prior to discharge; 71.1% of neonates had no evidence of hindbrain herniation on MRI. Of the 80 neonates evaluated, 55% were assigned a functional level of one or more better than the prenatal anatomic level. Conclusion: In an experienced program, maternal and neonatal outcomes for patients undergoing fMMC repair are comparable to results of the MOMS trial.

The role of echocardiography in the intraoperative management of the fetus undergoing myelomeningocele repair

INTRODUCTION

Fetal surgery for myelomeningocele (MMC) results in better outcomes compared to postnatal treatment. However, risks are present. We describe our experience with intraoperative fetal echocardiography during repair of MMC and report on the management of serious cardiovascular events.

MATERIAL AND METHODS

The subjects included fetuses with intent to repair MMC from January 2011 to February 2014. The protocol involved continuous echocardiography in a looping, sequential manner of systolic function, heart rate and tricuspid and mitral valve regurgitation.

RESULTS

A total of 101 cases intended fetal MMC repair; 100 completed surgery. Intraoperative ventricular dysfunction was present in 60% (20 mild, 25 moderate, 15 severe). Heart rate <100 bpm was noted in 11 cases. Tricuspid valve regurgitation was present in 35% (26 mild, 7 moderate, 2 severe); mitral valve regurgitation was present in 19% (15 mild, 4 moderate). Serious cardiovascular events were experienced in 7 cases, which affected the conduct of surgery and/or outcome. In 4 of these, medications were given via the umbilical vein and external cardiac compressions were performed. Fetal echocardiography was used to gauge the efficacy of compressions and to guide resuscitation.

DISCUSSION

Cardiovascular compromise is common during fetal surgery for MMC. Intraoperative fetal echocardiography is recommended as a growing number of centers contemplate offering this form of novel, but potentially risky, therapy.

Intraoperative neurophysiological monitoring in patients undergoing tethered cord surgery after fetal myelomeningocele repair

OBJECT

Fetal myelomeningocele closure has been shown to be advantageous in a number of areas. In this study, the authors report on neural function in patients who had previously undergone fetal myelomeningocele repair and returned to the authors' institution for further surgery that included intraoperative neurophysiological monitoring.

METHODS

The authors retrospectively reviewed data obtained in 6 cases involving patients who underwent fetal myelomeningocele repair and later returned to their institution for spinal cord untethering. (In 4 of the 6 cases, the patients also underwent removal of a dermoid cyst [3 cases] or removal of an epidermoid cyst [1 case] during the untethering procedure.) Records and imaging studies were reviewed to identify the anatomical level of the myelomeningocele as well as the functional status of each patient. Stimulated electromyography (EMG) and transcranial motor evoked potential (tcMEP) recordings obtained during surgery were reviewed to assess the functional integrity of the nerve roots and spinal cord.

RESULTS

During reexploration, all patients had reproducible signals at or below their anatomical level on stimulated EMG and tcMEP recordings. Corresponding to these findings, prior to tethering, all patients had antigravity muscle function below their anatomical level.

CONCLUSIONS

All 6 patients had lower-extremity function and neurophysiological monitoring recording signals at or below their anatomical level. These cases provide direct evidence of spinal cord and nerve root conductivity and functionality below the anatomical level of the myelomeningocele, further supporting that neurological status improves with fetal repair.

Fetal surgery for neural tube defects

A recently completed randomized, controlled, prospective multicenter trial, the Management of Myelomeningocele Study (MOMS), demonstrated that maternal-fetal surgery for myelomeningocele (MMC) before 26 weeks of gestation decreases the need for ventriculoperitoneal shunting, decreases hindbrain herniation, and preserves neurological function. However, the study also found that fetal MMC surgery is not without significant risks, such as premature delivery or maternal complications. The primary objective of this review is to provide a critical overview of the rationale for in-utero intervention for MMC in the context of pathological observations, animal models, initial clinical experience with human fetal MMC surgery, and the results of the randomized trial. The secondary objective is to briefly discuss our approach to fetal MMC. Finally, the ongoing clinical research and the recent developments of potential alternative fetal surgical techniques will be highlighted.

Twin reversed arterial perfusion sequence: a new method of parabiotic twin mass estimation correlated with pump twin compromise

OBJECTIVES

The purpose of this study was to test the hypothesis that using the formula of a prolate ellipsoid to estimate parabiotic twin mass correlates better with findings of pump twin compromise than using the sonographic method of Moore et al (Am J Obstet Gynecol 1990; 163:907-912).

METHODS

A 10-year retrospective review was performed to identify all cases of the suspected twin reversed arterial perfusion (TRAP) sequence. Parabiotic twin mass was estimated by summing body and extremity volumes calculated using the prolate ellipsoid formula (width × height × length × 0.523). Parabiotic twin mass was also estimated using the sonographic Moore method [1.21 × length(2) - (1.66 × length)]. Parabiotic twin mass estimated by both methods was correlated with sonographic findings associated with increased risk of pump twin compromise.

RESULTS

Fifty-nine pregnancies complicated by TRAP were identified. Using the prolate ellipsoid formula, the parabiotic twin mean sizes ± SD (as a percentage of pump twin weight) were 103.0% ± 52.0% and 56.9% ± 44.3% in cases with and without pump twin compromise (P = .0005), respectively. Using the sonographic Moore method, the mean parabiotic twin sizes were 122.9% ± 54.3% and 99.6% ± 62.8% in cases with and without pump twin compromise (P = .14). The median estimated masses of the parabiotic twin were 197 ± 219 g using the prolate ellipsoid formula and 310 ± 212 g using the sonographic Moore method (P = .0001). A parabiotic twin size greater than 70% of the pump twin correlated with findings associated with increased risk of pump twin compromise when using the prolate ellipsoid formula (P = .002) but not the sonographic Moore method (P = .09).

CONCLUSIONS

Sonographic findings associated with increased risk of pump twin compromise correlate better with prolate ellipsoid estimates of parabiotic twin mass. The median estimated mass of the parabiotic twin was statistically larger when calculated by the sonographic Moore method than by the prolate ellipsoid formula.

A vertical wall dominated by Acesta excavata and Neopycnodonte zibrowii, part of an undersampled group of deep-sea habitats

We describe a novel biotope at 633 to 762 m depth on a vertical wall in the Whittard Canyon, an extensive canyon system reaching from the shelf to the deep sea on Ireland’s continental margin. We explored this wall with an ROV and compiled a photomosaic of the habitat. The assemblage contributing to the biotope was dominated by large limid bivalves, Acesta excavata (mean shell height 10.4 cm), and deep-sea oysters, Neopycnodonte zibrowii, at high densities, particularly at overhangs. Mean density of N. zibrowii increased with depth, with densities of the most closely packed areas of A. excavata also increasing with depth. Other taxa associated with the assemblage included the solitary coral Desmophyllum dianthus, cerianthid anemones, comatulid crinoids, the trochid gastropod Margarites sp., the portunid crab Bathynectes longispina and small fish of the family Bythitidae. The scleractinian coral Madrepora oculata, the pencil urchin Cidaris cidaris and a species of Epizoanthus were also common. Prominent but less abundant species included the flytrap anemone Actinoscyphia saginata, the carrier crab Paramola cuvieri, and the fishes Lepidion eques and Conger conger. Observations of the hydrography of the canyon system identified that the upper 500 m was dominated by Eastern North Atlantic Water, with Mediterranean Outflow Water beneath it. The permanent thermocline is found between 600 and 1000 m depth, i.e., in the depth range of the vertical wall and the dense assemblage of filter feeders. Beam attenuation indicated nepheloid layers present in the canyon system with the greatest amounts of suspended material at the ROV dive site between 500 and 750 m. A cross-canyon CTD transect indicated the presence of internal waves between these depths. We hypothesise that internal waves concentrate suspended sediment at high concentrations at the foot of the vertical wall, possibly explaining the large size and high density of filter-feeding molluscs.

Perinatal management of congenital oropharyngeal tumors: the ex utero intrapartum treatment (EXIT) approach

PURPOSE

To present our experience in the perinatal management of fetuses with large oropharyngeal tumors by ex utero intrapartum treatment (EXIT).

METHODS

We performed a retrospective chart review of all patients with congenital oropharyngeal tumor who underwent an EXIT procedure between May 2006 and June 2012.

RESULTS

Four patients were included in the series, three females and one male. The diagnoses were epignathus (n=2) and congenital epulis (n=2). Three EXITs were done at term and one at late preterm due to premature rupture of membranes. Median maternal time under anesthesia was 185 min (range: 166-281) and median maternal operative time was 99 min (range: 85-153). Median maternal blood loss was 550 ml (range: 350-2000); one mother required a blood transfusion. Mean maternal hospital stay was 4 days. Median hysterotomy-to-cord clamp time was 24 min (range: 18-66). Mean fetal birth weight was 2.7 kg (range: 2.4-3). The airway was successfully accessed and secured under placental circulation in all cases. In the two patients with congenital epulis the tumors were resected at the base of their pedicles and the airway accessed via direct laryngoscopy before the umbilical cord was clamped. One patient with epignathus underwent a retrograde tracheal intubation under placental circulation and had the tumor resected thereafter. The second patient with epignathus had a tracheostomy done under placental circulation and then had tumor debulking immediately after the EXIT. The maternal morbidity was minimal and there were no mortalities.

CONCLUSIONS

We conclude that the EXIT procedure is the ideal delivery strategy for fetuses with prenatally diagnosed oropharyngeal tumors and potential airway obstruction at birth. Patients with prenatally diagnosed oropharyngeal tumors should be promptly referred to a fetal treatment center with a dedicated multidisciplinary team and EXIT capabilities.

Trackline and point detection probabilities for acoustic surveys of Cuvier's and Blainville's beaked whales

Acoustic survey methods can be used to estimate density and abundance using sounds produced by cetaceans and detected using hydrophones if the probability of detection can be estimated. For passive acoustic surveys, probability of detection at zero horizontal distance from a sensor, commonly called g(0), depends on the temporal patterns of vocalizations. Methods to estimate g(0) are developed based on the assumption that a beaked whale will be detected if it is producing regular echolocation clicks directly under or above a hydrophone. Data from acoustic recording tags placed on two species of beaked whales (Cuvier's beaked whale-Ziphius cavirostris and Blainville's beaked whale-Mesoplodon densirostris) are used to directly estimate the percentage of time they produce echolocation clicks. A model of vocal behavior for these species as a function of their diving behavior is applied to other types of dive data (from time-depth recorders and time-depth-transmitting satellite tags) to indirectly determine g(0) in other locations for low ambient noise conditions. Estimates of g(0) for a single instant in time are 0.28 [standard deviation (s.d.) = 0.05] for Cuvier's beaked whale and 0.19 (s.d. = 0.01) for Blainville's beaked whale.

Transcriptomics of cortical gray matter thickness decline during normal aging

INTRODUCTION

We performed a whole-transcriptome correlation analysis, followed by the pathway enrichment and testing of innate immune response pathway analyses to evaluate the hypothesis that transcriptional activity can predict cortical gray matter thickness (GMT) variability during normal cerebral aging.

METHODS

Transcriptome and GMT data were available for 379 individuals (age range=28-85) community-dwelling members of large extended Mexican American families. Collection of transcriptome data preceded that of neuroimaging data by 17 years. Genome-wide gene transcriptome data consisted of 20,413 heritable lymphocytes-based transcripts. GMT measurements were performed from high-resolution (isotropic 800 μm) T1-weighted MRI. Transcriptome-wide and pathway enrichment analysis was used to classify genes correlated with GMT. Transcripts for sixty genes from seven innate immune pathways were tested as specific predictors of GMT variability.

RESULTS

Transcripts for eight genes (IGFBP3, LRRN3, CRIP2, SCD, IDS, TCF4, GATA3, and HN1) passed the transcriptome-wide significance threshold. Four orthogonal factors extracted from this set predicted 31.9% of the variability in the whole-brain and between 23.4 and 35% of regional GMT measurements. Pathway enrichment analysis identified six functional categories including cellular proliferation, aggregation, differentiation, viral infection, and metabolism. The integrin signaling pathway was significantly (p<10(-6)) enriched with GMT. Finally, three innate immune pathways (complement signaling, toll-receptors and scavenger and immunoglobulins) were significantly associated with GMT.

CONCLUSION

Expression activity for the genes that regulate cellular proliferation, adhesion, differentiation and inflammation can explain a significant proportion of individual variability in cortical GMT. Our findings suggest that normal cerebral aging is the product of a progressive decline in regenerative capacity and increased neuroinflammation.

Fetoscopic laser therapy for twin-to-twin transfusion syndrome

Twin-to-twin transfusion syndrome (TTTS) is a unique and complicated phenomenon occurring in 10-15% of monochorionic gestations. The chronic unbalanced distribution of blood volume across placental anastomoses between the donor and recipient fetuses leads to multisystem organ impairment including maladaptive changes in both fetuses. Fetoscopic selective laser photocoagulation (SLPC) is now established as the primary treatment modality for advanced stages of TTTS. SLPC is also associated with a risk reduction in fetal demise and long-term neurological impairment.

Management of prenatally diagnosed lung lesions

Prenatal diagnosis provides insight into the in utero evolution of fetal thoracic lesions such as congenital cystic adenomatoid malformation (CCAM), bronchopulmonary sequestration (BPS), or hybrid lesions. Serial sonographic study of fetuses with thoracic lesions has helped define the natural history of these lesions, determine the pathophysiologic features that affect clinical outcome, and formulate in utero and postnatal management based on prognosis.

Habitat and ecology of Nephrops norvegicus

This review summarizes the data on habitat, population ecology and ecosystem roles of Nephrops norvegicus. The species has a broad range in the northeast Atlantic and Mediterranean, although it is possible that small or isolated patches of suitable habitat may not be occupied due to restrictions on larval supply. Nephrops densities are related to the silt-clay content of sediments, with interactions between habitat quality and density indicating competition for resources. An analysis of density-size interactions across fishery functional management units (FUs) suggests that growth is suppressed at high densities due to competition (e.g. in the western Irish Sea), although recruitment dynamics or size-selective mortality may also shape the size structure of populations. Nephrops biomass available across FUs may be similar, reflecting a constant yield due to the inverse relationship between individual size and population density. Gaps in the understanding of Nephrops' ecology reflect uncertain ageing criteria, reliance on fisheries-dependent data and few if any undisturbed habitats in which to examine fisheries-independent interactions.

Radiofrequency ablation vs bipolar umbilical cord coagulation in the management of complicated monochorionic pregnancies

OBJECTIVE

The application of radiofrequency ablation (RFA) termination procedures to complicated cases involving monochorionic twins offers the potential of a less invasive option when compared to endoscopic techniques. The purpose of this study was to compare outcomes between these two techniques.

METHODS

A retrospective review was undertaken of all cases of complicated monochorionic twin gestations treated at the Children's Hospital of Philadelphia from July 1996 to December 2010. Cases were identified from the fetal treatment database and data extracted in a uniform fashion from the patients' charts.

RESULTS

A total of 149 cases were identified with procedures performed on 146. Indications for selective termination of one fetus were twin reversed arterial perfusion sequence in 53, severe twin-to-twin transfusion syndrome in 43, discordance for fetal anomalies in 26 and selective intrauterine growth restriction in 24. Eighty-eight cases were managed with bipolar cord coagulation (BCC) and 58 with RFA. The procedures in all cases were technically successful in achieving selective termination. The mean gestational age at the time of the procedure was 20.9 ± 2.7 weeks in the BCC group vs 20.2 ± 2.2 weeks in the RFA group (P = 0.1). The median gestational age at delivery was 34.7 (interquartile range (IQR), 29.2-38.6) weeks for the BCC group vs 33.0 (IQR, 23.4-38.9) weeks in the RFA group (P = 0.073). Mean birth weight did not differ between the two groups. The procedure-to-delivery time was 87.1 ± 42.1 days for the BCC group vs 73.8 ± 47.2 days for the RFA group (P = 0.1). Overall survival was 85.2% in the BCC group vs 70.7% in the RFA group (P = 0.014). This was attributed primarily to a survival rate of 10.5% in the RFA group compared with 31.6% in the BCC group for cases where delivery occurred before 28 weeks' gestation (P = 0.01). Premature rupture of the membranes occurred in 27.3% in the BCC group vs 13.7% in the RFA group (P = 0.05). Preterm labor was more common in the BCC group than in the RFA group (22.4 vs 7%, respectively; P = 0.009).

CONCLUSION

Despite the smaller caliber of the instrument, RFA is not associated with a decrease in the overall complication rate for selective termination procedures. The technique used for selective termination should still be determined by technical considerations but patients should be informed of the survival rate associated with each technique.

Attitudes and perceptions towards substances among people with mental disorders: a systematic review

OBJECTIVE

To develop effective interventions for people with coexisting mental disorders (MD) and substance use, it may be beneficial to understand their attitudes and perceptions of substances.

METHOD

A systematic literature search regarding attitudes and perceptions towards tobacco, alcohol or cannabis among people with MD was conducted. Studies' methodological quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

Twenty-one papers were included in the review and found to have generally low methodological quality. Papers investigated reasons for substance use, substance use expectancies, substances' perceived effects and reasons for quitting. People with psychotic disorders reported using substances primarily for relaxation and pleasure. Among people with mood disorders, alcohol was used primarily for social motives and tobacco for negative affect reduction.

CONCLUSION

For substance use interventions among people with MD to be more effective, it may be necessary to tailor interventions specifically for this population and customize by substance type. Gaps in the literature regarding attitudes and perceptions towards substance use among people with MD were identified, which future research should aim to address. These include designing and conducting methodologically rigorous research, investigating perceived harmfulness and knowledge of substances, and broadening recruitment of participants to include people with MD other than psychosis.

Ex utero intrapartum treatment in the management of giant cervical teratomas

PURPOSE

The purpose of this study is to present the outcome and technical details of the Ex Utero Intrapartum Treatment (EXIT) procedure performed in the management of the fetus with a giant cervical teratoma.

METHODS

A retrospective review of the medical records of patients undergoing the EXIT procedure between September 1995 and September 2010 was performed.

RESULTS

Eighty-seven EXIT procedures were performed. In 20% of cases (17/87), the indication was giant cervical teratoma. There were 10 females and 7 males. Polyhydramnios was present in 82%. Median gestational age at EXIT was 35 weeks (range, 30-39 weeks). Median birth weight was 2.5 kg (range, 1.7-3.7 kg). Access to the airway under placental support was established in all cases via direct laryngoscopy/bronchoscopy in 8 patients (47%) and via surgical exploration (tracheostomy or retrograde intubation) in 9 patients (53%). The mortality rate under placental support was zero. Seven patients had the tumors resected immediately after the EXIT, 6 patients had the resection later, and 4 patients died before resection. The neonatal mortality rate was 23% (4/17 patients). Patients who died had severe pulmonary hypoplasia that resulted from the upward traction by the giant cervical mass on the airway and compression of the lungs against the thoracic apex.

CONCLUSIONS

We conclude that the EXIT procedure continues to be the optimal delivery strategy for patients with prenatally diagnosed giant cervical teratomas and potential airway obstruction at birth. A thorough evaluation of the prenatal images and an experienced multidisciplinary team are key factors for an effective approach to the obstructed fetal airway.

P-selectin Expression Tracks Cerebral Atrophy in Mexican-Americans

Background and Purpose: We hypothesized that the P-selectin (SELP) gene, localized to a region on chromosome 1q24, pleiotropically contributes to increased blood pressure and cerebral atrophy. We tested this hypothesis by performing genetic correlation analyses for 13 mRNA gene expression measures from P-selectin and 11 other genes located in 1q24 region and three magnetic resonance imaging derived indices of cerebral integrity. Methods: The subject pool consisted of 369 (219F; aged 28–85, average = 47.1 ± 12.7 years) normally aging, community-dwelling members of large extended Mexican-American families. Genetic correlation analysis decomposed phenotypic correlation coefficients into genetic and environmental components among 13 leukocyte-based mRNA gene expressions and three whole-brain and regional measurements of cerebral integrity: cortical gray matter thickness, fractional anisotropy of cerebral white matter, and the volume of hyperintensive WM lesions. Results: From the 13 gene expressions, significant phenotypic correlations were only found for the P- and L-selectin expression levels. Increases in P-selectin expression levels tracked with decline in cerebral integrity while the opposite trend was observed for L-selectin expression. The correlations for the P-selectin expression were driven by shared genetic factors, while the correlations with L-selectin expression were due to shared environmental effects. Conclusion: This study demonstrated that P-selectin expression shared a significant variance with measurements of cerebral integrity and posits elevated P-selectin expression levels as a potential risk factor of hypertension-related cerebral atrophy.

Fetal MRI-calculated total lung volumes in the prediction of short-term outcome in giant omphalocele: preliminary findings

OBJECTIVE

To determine the value of fetal MRI-calculated total lung volumes (TLV) in the prediction of short-term outcome in patients with giant omphalocele (GO).

MATERIAL AND METHODS

We reviewed all cases of GO undergoing fetal MRI after 21 weeks' gestation and receiving postnatal care at our institution between 2003 and 2010. Observed/expected (O/E) TLV was calculated using age-matched TLV normograms [Radiology 2001;219:236-241]. Postnatal outcomes were stratified based on O/E TLV above or below 50% of expected.

RESULTS

Seventeen GO cases fulfilled the entry criteria. The mean age at fetal MRI evaluation was 25.8 ± 4.8 weeks' gestation. The mean GO TLV (21.0 ± 13.2) was lower than age-matched population norms (p < 0.001), resulting in a mean O/E TLV of 52.3 ± 16.8%. The mean gestational age at delivery was 36.8 ± 1.6 weeks. Overall survival was 94%. Fourteen (88%) infants underwent staged reduction, and 2 underwent silver sulfadiazine treatment and delayed repair. Infants with ≤50% of predicted O/E TLV (n = 11, 65%) had lower Apgar scores at birth (p = 0.03), prolonged ventilatory support (p = 0.004), delayed oral intake (p = 0.03), and longer hospitalization (p = 0.03) compared to patients with ≥50% of expected O/E TLV. Two infants (both O/E TLV <50%) required tracheostomy placement.

CONCLUSION

In the assessment of GO fetuses, MRI-based O/E TLV of <50% was predictive of increased postnatal morbidity.

Fetal surgery for myelomeningocele: progress and perspectives

Myelomeningocele (MMC), one of the most common congenital malformations, can result in severe lifelong disabilities, including paraplegia, hydrocephalus, Chiari II malformation, bowel and bladder dysfunction, skeletal deformations, and neurocognitive impairment. Experimental studies provide compelling evidence that the neurological deficits associated with MMC are not simply caused by incomplete neurulation but rather by the prolonged exposure of the vulnerable neural elements to the intrauterine environment. MMC is the first non-lethal anomaly considered for fetal surgical intervention, necessitating a careful analysis of risks and benefits. Retrospective and prospective randomized studies suggest that fetal surgery of MMC before 26 weeks of gestation may preserve neuromotor function, reverse hindbrain herniation, and reduce the need for ventriculoperitoneal shunting. However, these studies also demonstrate that fetal surgery is associated with significant maternal and fetal risks. Consequently, additional research is necessary to further elucidate the pathophysiology of MMC, to define the ideal timing and technique of fetal closure, and to evaluate the long-term implications of prenatal intervention.

Following a foraging fish-finder: diel habitat use of Blainville's beaked whales revealed by echolocation

Simultaneous high resolution sampling of predator behavior and habitat characteristics is often difficult to achieve despite its importance in understanding the foraging decisions and habitat use of predators. Here we tap into the biosonar system of Blainville's beaked whales, Mesoplodon densirostris, using sound and orientation recording tags to uncover prey-finding cues available to echolocating predators in the deep-sea. Echolocation sounds indicate where whales search and encounter prey, as well as the altitude of whales above the sea-floor and the density of organisms around them, providing a link between foraging activity and the bio-physical environment. Tagged whales (n = 9) hunted exclusively at depth, investing most of their search time either in the lower part of the deep scattering layer (DSL) or near the sea-floor with little diel change. At least 43% (420/974) of recorded prey-capture attempts were performed within the benthic boundary layer despite a wide range of dive depths, and many dives included both meso- and bentho-pelagic foraging. Blainville's beaked whales only initiate searching when already deep in the descent and encounter prey suitable for capture within 2 min of the start of echolocation, suggesting that these whales are accessing prey in reliable vertical strata. Moreover, these prey resources are sufficiently dense to feed the animals in what is effectively four hours of hunting per day enabling a strategy in which long dives to exploit numerous deep-prey with low nutritional value require protracted recovery periods (average 1.5 h) between dives. This apparent searching efficiency maybe aided by inhabiting steep undersea slopes with access to both the DSL and the sea-floor over small spatial scales. Aggregations of prey in these biotopes are located using biosonar-derived landmarks and represent stable and abundant resources for Blainville's beaked whales in the otherwise food-limited deep-ocean.

Increased endoplasmic reticulum stress in decidual tissue from pregnancies complicated by fetal growth restriction with and without pre-eclampsia

OBJECTIVES

Endoplasmic reticulum (ER) stress has been implicated in both pre-eclampsia (PE) and fetal growth restriction (FGR), and is characterised by activation of three signalling branches: 1) PERK-pEIF2α, 2) ATF6 and 3) splicing of XBP1(U) into XBP1(S). To evaluate the contribution of ER stress in the pathogenesis of PE relative to FGR, we compared levels of ER stress markers in decidual tissue from pregnancies complicated by PE and/or FGR.

STUDY DESIGN

Whole-genome transcriptional profiling was performed on decidual tissue from women with PE (n = 13), FGR (n = 9), PE+FGR (n = 24) and controls (n = 58), and used for pathway and targeted transcriptional analyses of ER stress markers. The expression and cellular localisation of ER stress markers was assesses by Western blot and immunofluorescence analyses.

RESULTS

Increased ER stress was observed in FGR and PE+FGR, including both the PERK-pEIF2α and ATF6 signalling branches, whereas ER stress was less evident in isolated PE. However, these cases demonstrated elevated levels of XBP1(U) protein. ATF6 and XBP1 immunoreactivity was detected in most (>80%) extravillous trophoblasts, decidual cells and macrophages. No difference in the proportion of immunopositive cells or staining pattern was observed between study groups.

CONCLUSIONS

Increased PERK-pEIF2α and ATF6 signalling have been associated with decreased cellular proliferation and may contribute to the impaired placental growth characterising pregnancies with FGR and PE+FGR. XBP1(U) has been proposed as a negative regulator of ER stress, and increased levels in PE may reflect a protective mechanism against the detrimental effects of ER stress.

Preschool neurobehavioral outcome following fetal myelomeningocele surgery

OBJECTIVE

It was the aim of this study to assess the prevalence of preschool neurobehavioral problems in children following fetal myelomeningocele (fMMC) surgery.

METHODS

Prior to the Management of Myelomeningocele Study, 30 fMMC patients underwent a standardized neurodevelopmental examination at 5 years of age. The prevalence of behavioral problems was assessed by the Child Behavior Check List (CBCL), which includes a total problem score and 2 broad-band indices (internalizing and externalizing problems). fMMC children were classified as having normal, at-risk or clinically significant scores based on calculated T scores.

RESULTS

Twenty-two (73%) fMMC families completed the evaluation. Mean age at delivery following fMMC surgery was 35.5 ± 1.6 weeks. The prevalence of 'at-risk' or 'clinically significant' scores for internalizing, externalizing and total behavioral problems was similar to general population norms. No difference in overall internalizing (p = 0.19), externalizing (p = 0.54) and total behavioral (p = 0.18) scores was found between non-shunted and shunted fMMC children. However, shunted fMMC children were more likely to experience anxiety and depressive (p = 0.02), pervasive developmental (p = 0.03) and withdrawn (p = 0.06) behavior. Oppositional defiant, attention deficit and hyperactivity problems were not found. No correlation was found between overall neurodevelopmental outcome and abnormal CBCL scores.

CONCLUSIONS

fMMC surgery and subsequent preterm delivery is not associated with increased behavioral problems, impaired social interactions and restricted behavior patterns. Shunted fMMC children were more likely to have scores in the 'at-risk' or 'clinically significant' range for multiple CBCL subindices. Early detection of behavioral problems following fMMC surgery provides an opportunity for targeted and timely intervention enabling affected fMMC children to be socially successful.

Early delivery as an alternative management strategy for selected high-risk fetal sacrococcygeal teratomas

BACKGROUND

Large, prenatally diagnosed sacrococcygeal teratomas (SCTs) present a formidable challenge because of their unpredictable growth and propensity for complications. In our experience, even with aggressive serial imaging, many fetuses have died under a policy of "watchful waiting." We propose "early delivery" as the best option for selected cases of high-risk fetal SCT.

METHODS

The medical charts of all fetuses with SCT followed up at our institution and delivered before 32 weeks of gestation were reviewed for radiologic findings, fetal interventions, delivery information, perinatal inpatient course, and autopsy or discharge report.

RESULTS

Between 1996 and 2009, excluding those that underwent fetal surgery, 9 patients with fetal SCT were delivered before 32 weeks of gestation. Four had type I tumors, and 5 had type II tumors. Of the 9 fetuses, 4 survived the neonatal period. The only surviving patient delivered before 28 weeks underwent an ex utero intrapartum therapy procedure.

CONCLUSIONS

A significant number of pregnancies complicated by high-risk SCT will manifest signs of fetal or maternal decompensation, or both, between 27 and 32 weeks of gestation. In the absence of fulminant hydrops, preemptive early delivery can be associated with surprisingly good outcomes in appropriately selected fetuses with high-risk SCT.

A low COMT activity haplotype is associated with recurrent preeclampsia in a Norwegian population cohort (HUNT2)

The etiology of preeclampsia is complex, with susceptibility being attributable to multiple environmental factors and a large genetic component. Although many candidate genes for preeclampsia have been suggested and studied, the specific causative genes still remain to be identified. Catechol-O-methyltransferase (COMT) is an enzyme involved in catecholamine and estrogen degradation and has recently been ascribed a role in development of preeclampsia. In the present study, we have examined the COMT gene by genotyping the functional Val108/158Met polymorphism (rs4680) and an additional single-nucleotide polymorphism, rs6269, predicting COMT activity haplotypes in a large Norwegian case/control cohort (n(cases)= 1135, n(controls)= 2262). A low COMT activity haplotype is associated with recurrent preeclampsia in our cohort. This may support the role of redox-regulated signaling and oxidative stress in preeclampsia pathogenesis as suggested by recent studies in a genetic mouse model. The COMT gene might be a genetic risk factor shared between preeclampsia and cardiovascular diseases.

Fetal myelomeningocele surgery: preschool functional status using the Functional Independence Measure for children (WeeFIM)

OBJECTIVE

To study preschool functional status in children following fetal myelomeningocele (fMMC) surgery.

MATERIAL AND METHODS

Prior to the NICHD-MOMS trial, 30 fMMC underwent standardized neurodevelopmental examination at 5 years of age. Functional status was determined with the Functional Independence Measure (WeeFIM), which assesses self-care, mobility, and cognitive independence.

RESULTS

Evaluations were completed in 26 (87%). Mean cognitive (93.0 ± 21.9), self-care (66.5 ± 23.9), mobility (82.3 ± 19.5), and total (77.9 ± 20.3) functional quotient of fMMC children were significantly lower than age-matched population norms (P < 0.01). Complete caregiver independence was achieved by 22 (84%), 10 (38%), 16 (62%), and 15 (58%) fMMC children for cognition, self-care, mobility, and total functional outcome, respectively. Cognitive, mobility, and total independence were higher in non-shunted than shunted fMMC children (P = 0.02, P = 0.02, and P < 0.01, respectively) and in fMMC children with average neurodevelopmental scores (P < 0.001, P = 0.01, and P < 0.01, respectively). Self-care independence tended to be higher in the non-shunted group and in fMMC children with normal neurodevelopmental outcome (P = 0.07 and P = 0.09, respectively).

CONCLUSION

The majority of fMMC children achieved cognitive and mobility independence, but continue to require significant assistance in self-care. Non-shunted and fMMC children with normal neurodevelopmental outcome were more likely to be independent in daily living activities. Better understanding of the extent of functional limitations following fMMC surgery will allow for more effective early interventions geared toward maximizing independence in everyday tasks in all environments.

Open fetal surgery for myelomeningocele

Despite efforts at prevention through the use of preconception folic acid, spina bifida remains one of the most common congenital anomalies of the central nervous system that is compatible with life. It is, however, associated with a significant degree of lifelong morbidity. The development of open fetal surgery for myelomeningocele (MMC) has been a long process but one that serves as a model for how new procedures and technologies need to be properly evaluated before being brought into mainstream medical practice. Even so, risks and benefits need to be evaluated for each patient. The currently available studies have been carried out on a highly selected patient population where the fetal findings provided the maximum opportunity for benefit from prenatal closure of the MMC defect. There is the potential that as the surgery becomes more widely available, pressure will be brought to bear to perform surgery in cases where the likelihood for benefit is decreased and yet the risks are not. The only way to duplicate the results of the current studies is to follow the methodology and criteria that were used in the studies. This will mean that not every fetus with an MMC will be a candidate for in utero surgery. The balance of risk to benefit will continue to evolve as further technological advances are evaluated and more follow-up information is obtained.

A randomized trial of prenatal versus postnatal repair of myelomeningocele

BACKGROUND

Prenatal repair of myelomeningocele, the most common form of spina bifida, may result in better neurologic function than repair deferred until after delivery. We compared outcomes of in utero repair with standard postnatal repair.

METHODS

We randomly assigned eligible women to undergo either prenatal surgery before 26 weeks of gestation or standard postnatal repair. One primary outcome was a composite of fetal or neonatal death or the need for placement of a cerebrospinal fluid shunt by the age of 12 months. Another primary outcome at 30 months was a composite of mental development and motor function.

RESULTS

The trial was stopped for efficacy of prenatal surgery after the recruitment of 183 of a planned 200 patients. This report is based on results in 158 patients whose children were evaluated at 12 months. The first primary outcome occurred in 68% of the infants in the prenatal-surgery group and in 98% of those in the postnatal-surgery group (relative risk, 0.70; 97.7% confidence interval [CI], 0.58 to 0.84; P<0.001). Actual rates of shunt placement were 40% in the prenatal-surgery group and 82% in the postnatal-surgery group (relative risk, 0.48; 97.7% CI, 0.36 to 0.64; P<0.001). Prenatal surgery also resulted in improvement in the composite score for mental development and motor function at 30 months (P=0.007) and in improvement in several secondary outcomes, including hindbrain herniation by 12 months and ambulation by 30 months. However, prenatal surgery was associated with an increased risk of preterm delivery and uterine dehiscence at delivery.

CONCLUSIONS

Prenatal surgery for myelomeningocele reduced the need for shunting and improved motor outcomes at 30 months but was associated with maternal and fetal risks. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00060606.).

Fetal cardiovascular effects of lower urinary tract obstruction with giant bladder

OBJECTIVE

Lower urinary tract obstruction (LUTO) with massive bladder distension impacts on a variety of developing organ systems with consequent morbidity and mortality. The impact of LUTO on the fetal cardiovascular system has not previously been investigated. We hypothesize that a giant, distended bladder within the pelvis may cause vascular compression with observable consequences.

METHODS

Fetal echocardiography was performed in 42 fetuses with LUTO and compared with 35 normal controls matched for gestational age. Parameters investigated included cardiothoracic ratio, presence or absence of ventricular hypertrophy and pericardial effusion. Doppler echocardiographic examination of mitral and tricuspid valve inflow and the ductus venosus was performed. To assess arterial vascular impedance, pulsatility indices (PIs) were calculated for segments of the descending aorta and right and left iliac arteries (RIA and LIA).

RESULTS

In the LUTO group an increased cardiothoracic ratio was seen in nine (21%), ventricular hypertrophy in 12 (29%) and small pericardial effusion in 15 (36%). Filling characteristics of the right ventricle in the LUTO group demonstrated greater dependency upon atrial contraction, and ductus venosus flow demonstrated higher downstream impedance to filling, than in controls, suggesting altered compliance. The LUTO group also had lower distal descending aorta PI (1.53 ± 0.38 vs. 1.76 ± 0.44, P = 0.04), lower RIA-PI (1.31 ± 0.29 vs. 1.76 ± 0.44, P < 0.001) and lower LIA-PI (1.41 ± 0.44 vs. 1.73 ± 0.31, P < 0.01) than controls, suggesting vascular compression and increased impedance to flow.

CONCLUSIONS

LUTO with giant urinary bladder compresses the iliac arteries, which may lead to increased afterload. Further study is warranted to examine the impact of fetal treatment such as bladder drainage on these cardiovascular parameters.

STOX2 but not STOX1 is differentially expressed in decidua from pre-eclamptic women: data from the Second Nord-Trondelag Health Study

Variation in the Storkhead box-1 (STOX1) gene has previously been associated with pre-eclampsia. In this study, we assess candidate single nucleotide polymorphisms (SNPs) in STOX1 in an independent population cohort of pre-eclamptic (n = 1.139) and non-pre-eclamptic (n = 2.269) women (the HUNT2 study). We also compare gene expression levels of STOX1 and its paralogue, Storkhead box-2 (STOX2) in decidual tissue from pregnancies complicated by pre-eclampsia and/or fetal growth restriction (FGR) (n = 40) to expression levels in decidual tissue from uncomplicated pregnancies (n = 59). We cannot confirm association of the candidate SNPs to pre-eclampsia (P > 0.05). For STOX1, no differential gene expression was observed in any of the case groups, whereas STOX2 showed significantly lower expression in deciduas from pregnancies complicated by both pre-eclampsia and FGR as compared with controls (P = 0.01). We further report a strong correlation between transcriptional alterations reported previously in choriocarcinoma cells over expressing STOX1A and alterations observed in decidual tissue of pre-eclamptic women with FGR.

Paradoxical effects of the cannabinoid CB2 receptor agonist GW405833 on rat osteoarthritic knee joint pain

OBJECTIVE

The present study examined whether local administration of the cannabinoid-2 (CB(2)) receptor agonist GW405833 could modulate joint nociception in control rat knee joints and in an animal model of osteoarthritis (OA).

METHOD

OA was induced in male Wistar rats by intra-articular injection of sodium monoiodo-acetate with a recovery period of 14 days. Immunohistochemistry was used to evaluate the expression of CB(2) and transient receptor potential vanilloid channel-1 (TRPV1) receptors in the dorsal root ganglion (DRG) and synovial membrane of sham- and sodium mono-iodoacetate (MIA)-treated animals. Electrophysiological recordings were made from knee joint primary afferents in response to rotation of the joint both before and following close intra-arterial injection of different doses of GW405833. The effect of intra-articular GW405833 on joint pain perception was determined by hindlimb incapacitance. An in vitro neuronal release assay was used to see if GW405833 caused release of an inflammatory neuropeptide (calcitonin gene-related peptide - CGRP).

RESULTS

CB(2) and TRPV1 receptors were co-localized in DRG neurons and synoviocytes in both sham- and MIA-treated animals. Local application of the GW405833 significantly reduced joint afferent firing rate by up to 31% in control knees. In OA knee joints, however, GW405833 had a pronounced sensitising effect on joint mechanoreceptors. Co-administration of GW405833 with the CB(2) receptor antagonist AM630 or pre-administration of the TRPV1 ion channel antagonist SB366791 attenuated the sensitising effect of GW405833. In the pain studies, intra-articular injection of GW405833 into OA knees augmented hindlimb incapacitance, but had no effect on pain behaviour in saline-injected control joints. GW405833 evoked increased CGRP release via a TRPV1 channel-dependent mechanism.

CONCLUSION

These data indicate that GW405833 reduces the mechanosensitivity of afferent nerve fibres in control joints but causes nociceptive responses in OA joints. The observed pro-nociceptive effect of GW405833 appears to involve TRPV1 receptors.