Radiographic and histologic characterisation of white matter injury in a sheep model of CHD.

Nearly one in five children with CHD is born with white matter injury that can be recognised on postnatal MRI by the presence of T1 hyperintense lesions. This pattern of white matter injury is known to portend poor neurodevelopmental outcomes, but the exact aetiology and histologic characterisation of these lesions have never been described. A fetal sheep was cannulated at gestational age 110 days onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid environment for 14.5 days. The fetus was supported under hypoxic conditions (mean oxygen delivery 16 ml/kg/day) to simulate the in utero conditions of CHD. At necropsy, the brain was fixed, imaged with MRI, and then stained to histologically identify areas of injury. Under hypoxemic in utero conditions, the fetus developed a T1 hyperintense lesion in its right frontal lobe. Histologically, this lesion was characterised by microvascular proliferation and astrocytosis without gliosis. These findings may provide valuable insight into the aetiology of white matter injury in neonates with CHD.

Surgical insights and management in patients with the 22q11.2 deletion syndrome.

PURPOSE: 22q11.2 deletion syndrome (22q11.2DS) can present with a variety challenges to patients and their caregivers, many of which require surgical evaluation and intervention. Surgical needs can also extend long into adulthood, prompting evaluation and intervention throughout development and beyond. Here, we identify common concerns and patient needs associated with the 22q11.2DS from a general surgery perspective, their management, and typical management based on our institution's experience with 1263 patients. METHODS: 1263 patients evaluated and treated at the 22q And You Center at the Children's Hospital of Philadelphia were enrolled and included in the study, from January 1992 to May 2017 Co-morbidities, procedures, and imaging studies performed were quantified and assessed via descriptive analysis. RESULTS: Gastroesophageal reflux disease (GERD) and feeding difficulties were the most common surgical issues identified, while gastrostomy tube placement, anorectal procedures, and hernia repairs were the most common surgical interventions performed by general surgeons. CONCLUSIONS: General surgical procedures are commonly needed in this population and are part of the complex needs these patients and their surgeons may encounter in the setting of a 22q11.2DS diagnosis. These findings will help to inform a well-coordinated, multidisciplinary approach to care.

Chronic foetal hypoxaemia does not cause elevation of serum markers of brain injury.

OBJECTIVES: The objective of this study was to investigate changes in serum biomarkers of acute brain injury, including white matter and astrocyte injury during chronic foetal hypoxaemia. We have previously shown histopathological changes in myelination and neuronal density in fetuses with chronic foetal hypoxaemia at a level consistent with CHD. METHODS: Mid-gestation foetal sheep (110 ± 3 days gestation) were cannulated and attached to a pumpless, low-resistance oxygenator circuit, and incubated in a sterile fluid environment mimicking the intrauterine environment. Fetuses were maintained with an oxygen delivery of 20-25 ml/kg/min (normoxemia) or 14-16 ml/kg/min (hypoxaemia). Myelin Basic Protein and Glial Fibrillary Acidic Protein serum levels in the two groups were assessed by ELISA at baseline and at 7, 14, and 21 days of support. RESULTS: Based on overlapping 95% confidence intervals, there were no statistically significant differences in either Myelin Basic Protein or Glial Fibrillary Acidic Protein serum levels between the normoxemic and hypoxemic groups, at any time point. No statistically significant correlations were observed between oxygen delivery and levels of Myelin Basic Protein and Glial Fibrillary Acidic Protein. CONCLUSION: Chronic foetal hypoxaemia during mid-gestation is not associated with elevated serum levels of acute white matter (Myelin Basic Protein) or astrocyte injury (Glial Fibrillary Acidic Protein), in this model. In conjunction with our previously reported findings, our data support the hypothesis that the brain dysmaturity with impaired myelination found in fetuses with chronic hypoxaemia is caused by disruption of normal developmental pathways rather than by direct cellular injury.

Evaluation of umbilical venous flow volume measured using ultrasound compared to circuit flow volume in the EXTra-uterine Environment for Neonatal Development (EXTEND) system in fetal sheep.

OBJECTIVE: To compare and validate umbilical venous flow volume (UVFV) measured at the intra-abdominal portion using ultrasound with actual flow volume of umbilical vein (UV) in fetal sheep sustained on the EXTrauterine Environment for Neonatal Development (EXTEND) system. METHODS: Circuit flow volume through the oxygenator was obtained using sensors. Ultrasound derived UVFV (ml/min) was calculated as (UV diameter [cm]/2)2 × 3.14 × maximum velocity (cm/s) × 0.5 × 60, measured at approximately the mid portion between its abdominal insertion and the origin of the ductus venosus. UVFV was measured by ultrasound once daily and was compared to the average of daily circuit flow volume directly measured. RESULTS: UVFV was measured 168 times in 15 fetal sheep. The ratio of circuit flow volume to combined cardiac output remained stable within the anticipated physiological range throughout. UVFV measured by ultrasound showed good correlation to directly measured circuit flow (r = 0.72). Interclass correlation coefficients for intra-observer variability was 0.991 (95% confidence interval [CI], 0.979-0.996). CONCLUSION: UVFV measured at the intra-abdominal portion using ultrasound shows a good correlation with directly measured circuit flow volume in UV of fetal sheep on the EXTEND system. Regular incorporation of such validated UVFV measures into clinical use may offer opportunities to better understand conditions of placental dysfunction.

Audit of blood product utilization in the care of injured children.

BACKGROUND: Blood product utilization in injured children is poorly characterized; the decision to prepare products or transfuse patients can be difficult due to a lack of reliable evidence of transfusion needs across pediatric age-groups and injury types. We conducted an audit of transfusion practices in pediatric trauma based on age, injuries, and mechanism of injury. METHODS: We reviewed and cross-referenced blood product transfusion practice data from the trauma registry and the anesthesia transfusion record database at a level 1 pediatric trauma center over a 10-year period. Demographic data, injury severity scores, and survival statistics were obtained from the trauma registry. Transfusion rates are reported separately for hospital admission and for intraoperative transfusions for procedures performed during the first two hospital days. Descriptive statistical analysis was used to compare specific groups based on age, injury type, and mechanism of injury. RESULTS: We report 14 569 trauma admissions of 14 606 patients. The transfusion rate during the admission was 1.56% (227/14 569). 4591 (30.9%) admissions had surgical interventions in first two days of hospitalization with an intraoperative transfusion rate of 2.98%. Patients younger than one year had the highest transfusion rate during admission (2.8%), and the highest transfusion rate during surgical procedures performed in the first two days of the admission (18.87%). Admissions due to vascular injuries had the highest transfusion rates in infancy followed by hollow visceral injuries in adolescents (71.4% and 25%, respectively). Vascular injuries in most age-groups also had high transfusion rates ranging from 11% in 5- to 9-year age-group to 71% in infants. Mechanisms with the highest transfusion rates were firearm wounds in patients older than one year and vehicular accidents for patients younger than one year. CONCLUSIONS: The overall blood product needs in the pediatric trauma population are low (1.56%). Selected populations requiring higher rates of need include infants younger than one year, and children with thoracic and vascular injuries. Understanding transfusion patterns is important to optimize resource allocation.

The EXTrauterine Environment for Neonatal Development Supports Normal Intestinal Maturation and Development.

BACKGROUND AND AIMS: The Extra-Uterine Environment for Neonatal Development (EXTEND) aims to avoid the complications of prematurity, such as NEC. Our goal was to determine if bowel development occurs normally in EXTEND-supported lambs, with specific emphasis on markers of immaturity associated with NEC. METHODS: We compared terminal ileum from 17 pre-term lambs supported on EXTEND for 2- 4 weeks to bowel from age-matched fetal lambs that developed in utero. We evaluated morphology, markers of epithelial integrity and maturation, enteric nervous system structure, and bowel motility. RESULTS: EXTEND-supported lamb ileum had normal villus height, crypt depth, density of mucin-containing goblet cells, and enteric neuron density. Expression patterns for I-FABP, activated caspase-3 and EGFR were normal in bowel epithelium. Transmural resistance assessed in Ussing chambers was normal. Bowel motility was also normal as assessed by ex vivo organ bath and video imaging. However, Peyer's patch organization did not occur normally in EXTEND ileum, resulting in fewer circulating B cells in experimental animals. CONCLUSION: EXTEND supports normal ileal epithelial and enteric nervous system maturation in pre-term lambs. The classic morphologic changes and cellular expression profiles associated with NEC are not seen. However, immune development within the EXTEND supported lamb bowel does not progress normally.

Survival of white-tailed deer fawns in central Iowa.

Understanding demographic parameters such as survival is important for scientifically sound wildlife management. Survival can vary by region, sex, age-class, habitat, and other factors. White-tailed deer fawn survival is highly variable across the species' range. While recent studies have investigated fawn survival in several Midwestern states, there have been no published estimates from Iowa for 30 years. We radio-collared 48 fawns in central Iowa from 2015-2017 to estimate survival, home range size, and habitat composition and identity causes of mortality. Estimated fawn survival (± SE) was similar to other Midwest studies at 30 (0.78 ± 0.07)) and 60 days (0.69 ± 0.08), but considerably lower at 7 months (0.31 ± 0.02). Survival was positively associated with woodland habitat through 30 and 60 days, but not related to habitat at 7 months. Female fawns avoided agricultural habitat in their home ranges. Fawn 95% kernel density home ranges were smaller than in other studies in the Midwest (21.22 ± 2.74 ha at 30 days, 25.47 ± 2.87 ha at 60 days, and 30.59 ± 2.37 ha at 7 months). The large amount of woodland and grassland (>90%) in our study area meant that fawns did not have to travel far to find suitable cover, which may explain their small home ranges. We recorded 21 mortalities, the leading cause of which was disease (n = 9; 56% epizootic hemorrhagic disease [EHD]) followed by suspected predation (4) and harvest (3). The mortality associated with an outbreak of EHD in 2016, all of which occurred after 60 days post-capture, is the most likely explanation for our low survival estimate at 7 months. While predation, usually early in life, is the leading cause of mortality in most studies, sporadic diseases like EHD can be a major source of mortality in older fawns in some years.

Neurologic outcomes of the premature lamb in an extrauterine environment for neonatal development.

BACKGROUND/PURPOSE: Neurologic injury remains the most important morbidity of prematurity. Those born at the earliest gestational ages can face a lifetime of major disability. Perinatal insults result in developmental delay, cerebral palsy, and other profound permanent neurologic impairments. The EXTracorporeal Environment for Neonatal Development (EXTEND) aims to transition premature neonates through this sensitive period, but it's impact on neurologic development requires analysis. METHODS: Fetal sheep were maintained in a fluid-filled environment for up to 28 days. Physiologic parameters were measured continuously; tissues were subsequently fixed and preserved for myelin quantification, glial cell staining, and structural assessment via magnetic resonance. Surviving animals were functionally assessed. RESULTS: No evidence of fetal brain ischemia or white matter tract injury associated with the EXTEND system was detected, and the degree of myelination was regionally appropriate and consistent with age matched controls. No evidence of neurologic injury or immaturity was visible on magnetic resonance; animals that transitioned from the system had no persistent neurologic deficits. CONCLUSIONS: No evidence of major neurologic morbidity was found in animals supported on the EXTEND system, though more work needs to be done in order to verify its safety during critical periods of neurologic development.

Ex Utero Extracorporeal Support as a Model for Fetal Hypoxia and Brain Dysmaturity.

BACKGROUND: Congenital heart disease (CHD) is associated with abnormal fetal brain development, a phenomenon that may be related to decreased cerebral oxygen delivery in utero. We used an artificial womb model to test the hypothesis that decreasing fetal oxygen delivery would reproduce physiologic changes identified in fetuses with CHD. METHODS: Experimental (hypoxemic) fetal lambs (mean gestational age, 111 ± 3 days; n = 4) and control animals (112 days; n = 5) were maintained in the artificial womb for a mean of 22 ± 6 days. Oxygen delivery was reduced to 15.6 ± 1.0 mL/kg/min in the hypoxemia animals versus 21.6 ± 2.0 mL/kg/min in the control animals. Blood chemistry analysis and sonographic evaluation were performed daily. An additional control group (n = 7) was maintained in utero and harvested for analysis at gestational age 134 ± 4 days. RESULTS: Physiologic variables were monitored continuously, and no statistical differences between the groups were identified. Fetal oxygen delivery and arterial partial pressure of oxygen were remarkably lower in the experimental group longitudinally. Increased umbilical artery and decreased middle cerebral artery resistance resulted in a lower cerebral to umbilical resistance ratio, similar to the brain sparing effect observed in human fetuses with CHD. Experimental brains were smaller than control brains in relation to the calvarium on magnetic resonance. CONCLUSIONS: Sustained hypoxemia in fetal sheep leads to altered cerebrovascular resistances and loss of brain mass, similar to human fetuses with CHD. This unique model provides opportunities to investigate the pathologic process underlying CHD-associated brain dysmaturity and to evaluate potential fetal neuroprotective therapies.

Prenatal hypoxemia alters microglial morphology in fetal sheep.

OBJECTIVE: Neuroimmune cells, particularly microglia and astrocytes, play a critical role in neurodevelopment. Neurocognitive delays are common in children with congenital heart disease, but their etiology is poorly understood. Our objective was to determine whether prenatal hypoxemia, at levels common in congenital heart disease, induced neuroimmune activation to better understand the origins of neurobehavioral disorders in congenital heart disease. METHODS: Eight fetal sheep at gestational age 109 ± 3 days (term ∼145 days) were cannulated onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid environment for 22 ± 2 days under normoxic (n = 4) or hypoxic (n = 4) conditions. Control fetuses (n = 7) were harvested at gestational age 133 ± 4 days. At necropsy, brains were stained with ionized calcium-binding adaptor molecule 1 and glial fibrillary acidic protein antibodies to quantify microglia and astrocytes, respectively, in gray and white matter in frontotemporal and cerebellar sections. Microglia were classified into 4 morphologic types based on cell shape. Data were analyzed with 1-way analysis of variance or Fisher exact test, as appropriate. RESULTS: Oxygen delivery was significantly reduced in hypoxic fetuses (15.6 ± 1.8 mL/kg/min vs 24.3 ± 2.3 mL/kg/min; P < .01). Rates of apoptosis were similar in hypoxic, normoxic, and intrauterine control animals in all examined areas. There were also no differences between groups in area occupied by glial fibrillary acidic protein-labeled astrocytes or ionized calcium-binding adaptor molecule 1-labeled microglia in all examined areas. However, round microglia were significantly increased in hypoxic animals compared with normoxic animals (33% vs 6%; P < .01) and control animals (33% vs 11%; P < .01). CONCLUSIONS: Prenatal hypoxemia altered microglial morphology without significant gliosis. Additional studies characterizing these mechanisms may provide insight into the origins of neurobehavioral disabilities in children with congenital heart disease.

Technical feasibility of umbilical cannulation in midgestation lambs supported by the EXTra-uterine Environment for Neonatal Development (EXTEND).

EXTEND (EXTra-uterine Environment for Neonatal Development) is a novel system for supporting extremely premature infants that replicates in utero conditions by maintaining a sterile fluid environment and providing gas exchange via a pumpless arteriovenous oxygenator circuit connected to the umbilical vessels. Target gestational age (GA) for EXTEND support in human infants is 23-27 weeks, when immature lungs are most susceptible to injury in the setting of air ventilation. We previously demonstrated physiologic support of premature lambs cannulated at 105-117 days GA (lungs developmentally analogous to the 23-27 week GA human infant) for up to 28 days on EXTEND. In the present study, we sought to determine the technical feasibility of umbilical vessel cannulation in 85-96 days GA lambs delivered to EXTEND at weights equivalent to the 23-27 week GA human infant (500-850 g). Five preterm lambs were cannulated at 85-96 days GA (term 145 days) and supported on EXTEND for 4-7 days. All lambs underwent umbilical artery and umbilical vein cannulation. Circuit flows and pressures were monitored continuously, and blood gases were obtained at regular intervals for assessment of oxygen parameters. Systemic pH and lactate were measured at least once daily. Mean body weight at cannulation was 641 ± 71 g (range 480-850 g). All lambs were cannulated successfully (cannula size varied from 8 to 12 Fr), and mean survival on EXTEND was 140 ± 7 hours. Mean circuit flow was 213 ± 15 mL/kg*min, mean pH was 7.37 ± 0.01, and mean lactate was 1.6 ± 0.2 mmol/L. During the initial 120 hours after EXTEND cannulation, there were no significant differences between 85-96 days GA lambs and 105-117 days GA lambs in weight-adjusted circuit flows, oxygen delivery, pH, or lactate levels. This study demonstrates successful umbilical cord cannulation and adequate circuit flows and oxygen delivery in midgestation lambs size-matched to the 23-27 week GA human fetus, which represents an important step in the translation of EXTEND to clinical practice.

Chronic intrauterine hypoxia alters neurodevelopment in fetal sheep.

OBJECTIVE: We tested the hypothesis that chronic fetal hypoxia, at a severity present in many types of congenital heart disease, would lead to abnormal neurodevelopment. METHODS: Eight mid-gestation fetal sheep were cannulated onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid-filled environment for 22 ± 2 days under normoxic or hypoxic conditions. Total parenteral nutrition was provided. Control fetuses (n = 7) were harvested at gestational age 133 ± 4 days. At necropsy, brains were fixed for histopathology. Neurons were quantified in white matter tracts, and the thickness of the external granular layer of the cerebellum was measured to assess neuronal migration. Capillary density and myelination were quantified in white matter. Data were analyzed with unpaired Student t tests or 1-way analysis of variance, as appropriate. RESULTS: Oxygen delivery was reduced in hypoxic fetuses (15.6 ± 1.8 mL/kg/min vs 24.3 ± 2.3 mL/kg/min, P < .01), but umbilical blood flow and caloric delivery were not different between the 2 groups. Compared with normoxic and control animals, hypoxic fetuses had reduced neuronal density and increased external granular layer thickness. Compared with normoxic and control animals, hypoxic fetuses had increased capillary density in white matter. Cortical myelin integrity score was lower in the hypoxic group compared with normoxic and control animals. There was a significant negative correlation between myelin integrity and capillary density. CONCLUSIONS: Chronic fetal hypoxia leads to white matter hyper-vascularity, decreased neuronal density, and impaired myelination, similar to the neuropathologic findings observed in children with congenital heart disease. These findings support the hypothesis that fetal hypoxia, even in the setting of normal caloric delivery, impairs neurodevelopment.

Erythropoietin Prevents Anemia and Transfusions in Extremely Premature Lambs Supported by an EXTrauterine Environment for Neonatal Development (EXTEND).

BACKGROUND: We recently developed an EXTrauterine Environment for Neonatal Development (EXTEND) that provides physiologic support for premature lambs. Here, we assess the efficacy of exogenous erythropoietin (EPO) to prevent anemia and transfusions on EXTEND. MATERIALS AND METHODS: Lambs were cannulated at 0.7 gestation and supported on EXTEND for up to 4 weeks. The lambs were divided into three groups: (1) No EPO, (2) Low EPO (300 U kg-1 per day), and (3) High EPO (800 U kg-1 per day). Daily hematocrit and weekly complete blood count were assessed. RESULTS: The mean percentage change in hematocrit from baseline was significantly different between the groups (No EPO -23.6 ± 7.8% vs. Low EPO -16.6 ± 6.4% vs. High EPO +2.6 ± 6.6%; p = 0.02). This occurred despite a greater median number of blood transfusions in the No EPO group (5 vs. 1 vs. 0; p = 0.02). EPO administration was associated with a higher mean corpuscular volume (MCV; p < 0.01) and reticulocyte count (p = 0.02). The High EPO group was comparable to in utero control fetuses with respect to hematocrit (p = 0.49), MCV (p = 0.24), and reticulocyte count (p = 0.68). CONCLUSIONS: EPO (800 U kg-1 per day) prevents anemia, eliminates transfusions, and restores normal red blood cell indices in premature lambs supported by EXTEND.

Chronically Hypoxic Fetal Lambs Supported by an Extra-Uterine Device Exhibit Mitochondrial Dysfunction and Elevations of Hypoxia Inducible Factor 1-Alpha.

INTRODUCTION: We have recently developed an extra-uterine environment for neonatal development (EXTEND) capable of supporting premature fetal lambs and have been able to replicate hypoxic in utero conditions by controlling fetal oxygen delivery. In this study, we investigated the fetal mitochondrial response to hypoxia. METHODS: Eight premature fetal lambs were delivered via hysterotomy and transitioned to extra-uterine support for 3 weeks. The lambs were divided into 2 groups: normoxic fetuses which maintained physiologic oxygen delivery and hypoxic fetuses in which oxygen delivery was significantly reduced. Control fetuses were delivered via hysterotomy but not cannulated. Measurements of mitochondrial membrane potential (MMP) were performed in peripheral blood mononuclear cells. RESULTS: There were no significant differences in MMP between normoxic EXTEND fetuses and controls. Hypoxic fetuses had significantly more depolarized mitochondria compared to normoxic fetuses overall, and these changes were specifically appreciated in weeks 1 and 2, but not by week 3. Hypoxic fetuses had significantly elevated levels of HIF-1α compared to normoxic fetuses in the first 2 weeks. DISCUSSION: Normoxic fetal lambs supported by EXTEND demonstrate normal mitochondrial function as evidenced by equivalent membrane potentials compared to control fetuses. Hypoxic fetuses exhibit mitochondrial dysfunction, though they do show evidence of adaptation after 3 weeks of hypoxic exposure.

Fetal hypoxemia causes abnormal myocardial development in a preterm ex utero fetal ovine model.

In utero hypoxia is a major cause of neonatal morbidity and mortality and predisposes to adult cardiovascular disease. No therapies exist to correct fetal hypoxia. In a new ex utero fetal support system, we tested the hypothesis that hypoxemic support of the fetus impairs myocardial development, whereas normoxic support allows normal myocardial development. Preterm fetal lambs were connected via umbilical vessels to a low-resistance oxygenator and placed in a sterile-fluid environment. Control normoxic fetuses received normal fetal oxygenation, and hypoxemic fetuses received subphysiologic oxygenation. Fetuses with normal in utero development served as normal controls. Hypoxemic fetuses exhibited decreased maximum cardiac output in both ventricles, diastolic function, myocyte and myocyte nuclear size, and increased myocardial capillary density versus control normoxic fetuses. There were no differences between control normoxic fetuses in the fetal support system and normal in utero controls. Chronic fetal hypoxemia resulted in significant abnormalities in myocyte architecture and myocardial capillary density as well as systolic and diastolic cardiac function, whereas control fetuses showed no differences. This ex utero fetal support system has potential to become a significant research tool and novel therapy to correct fetal hypoxia.

Ring faults and ring dikes around the Orientale basin on the Moon.

The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having experienced only modest modification by subsequent impacts and volcanism. Orientale is often treated as the type example of a multiring basin, with three prominent rings outside of the inner depression: the Inner Rook Montes, the Outer Rook Montes, and the Cordillera. Here we use gravity data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to reveal the subsurface structure of Orientale and its ring system. Gradients of the gravity data reveal a continuous ring dike intruded into the Outer Rook along the plane of the fault associated with the ring scarp. The volume of this ring dike is ~18 times greater than the volume of all extrusive mare deposits associated with the basin. The gravity gradient signature of the Cordillera ring indicates an offset along the fault across a shallow density interface, interpreted to be the base of the low-density ejecta blanket. Both gravity gradients and crustal thickness models indicate that the edge of the central cavity is shifted inward relative to the equivalent Inner Rook ring at the surface. Models of the deep basin structure show inflections along the crust-mantle interface at both the Outer Rook and Cordillera rings, indicating that the basin ring faults extend from the surface to at least the base of the crust. Fault dips range from 13-22° for the Cordillera fault in the northeastern quadrant, to 90° for the Outer Rook in the northwestern quadrant. The fault dips for both outer rings are lowest in the northeast, possibly due to the effects of either the direction of projectile motion or regional gradients in pre-impact crustal thickness. Similar ring dikes and ring faults are observed around the majority of lunar basins.

Umbilical cannulation optimizes circuit flows in premature lambs supported by the EXTra-uterine Environment for Neonatal Development (EXTEND).

KEY POINTS: Bronchopulmonary dysplasia is a disease of extreme prematurity that occurs when the immature lung is exposed to gas ventilation. We designed a novel 'artificial womb' system for supporting extreme premature lambs (called EXTEND) that obviates gas ventilation by providing oxygen via a pumpless arteriovenous circuit with the lamb submerged in sterile artificial amniotic fluid. In the present study, we compare different arteriovenous cannulation strategies on EXTEND, including carotid artery/jugular vein (CA/JV), carotid artery/umbilical vein (CA/UV) and umbilical artery/umbilical vein (UA/UV). Compared to CA/JV and CA/UV cannulation, UA/UV cannulation provided significantly higher, physiological blood flows to the oxygenator, minimized flow interruptions and supported significantly longer circuit runs (up to 4 weeks). Physiological circuit blood flow in UA/UV lambs made possible normal levels of oxygen delivery, which is a critical step toward the clinical application of artificial womb technology. ABSTRACT: EXTEND (EXTra-uterine Environment for Neonatal Development) is a novel system that promotes physiological development by maintaining the premature lamb in a sterile fluid environment and providing gas exchange via a pumpless arteriovenous oxygenator circuit. During the development of EXTEND, different cannulation strategies evolved with the aim of improving circuit flow. The present study examines how different cannulation strategies affect EXTEND circuit haemodynamics in extreme premature lambs. Seventeen premature lambs were cannulated at gestational ages 105-117 days (term 145-150 days) and supported on EXTEND for up to 4 weeks. Experimental groups were distinguished by cannulation strategy: carotid artery outflow and jugular vein inflow (CA/JV; n = 4), carotid artery outflow and umbilical vein inflow (CA/UV; n = 5) and double umbilical artery outflow and umbilical vein inflow (UA/UV; n = 8). Circuit flows and pressures were measured continuously. As we transitioned from CA/JV to CA/UV to UA/UV cannulation, mean duration of circuit run and weight-adjusted circuit flows increased (P < 0.001) and the frequency of flow interruptions declined (P < 0.05). Umbilical vessels generally accommodated larger-bore cannulas, and cannula calibre was directly correlated with circuit pressures and indirectly correlated with flow:pressure ratio (a measure of post-membrane resistance). We conclude that UA/UV cannulation in fetal lambs on EXTEND optimizes circuit flow dynamics and flow stability and also supports circuit flows that closely approximate normal placental flow.

Early Neolithic wine of Georgia in the South Caucasus.

Chemical analyses of ancient organic compounds absorbed into the pottery fabrics from sites in Georgia in the South Caucasus region, dating to the early Neolithic period (ca. 6,000-5,000 BC), provide the earliest biomolecular archaeological evidence for grape wine and viniculture from the Near East, at ca. 6,000-5,800 BC. The chemical findings are corroborated by climatic and environmental reconstruction, together with archaeobotanical evidence, including grape pollen, starch, and epidermal remains associated with a jar of similar type and date. The very large-capacity jars, some of the earliest pottery made in the Near East, probably served as combination fermentation, aging, and serving vessels. They are the most numerous pottery type at many sites comprising the so-called "Shulaveri-Shomutepe Culture" of the Neolithic period, which extends into western Azerbaijan and northern Armenia. The discovery of early sixth millennium BC grape wine in this region is crucial to the later history of wine in Europe and the rest of the world.

Corrigendum: An extra-uterine system to physiologically support the extreme premature lamb.

This corrects the article DOI: 10.1038/ncomms15112.