Factors Associated with Hospital Readmission One Year Post-Discharge in Infants with Gastroschisis

INTRODUCTION

Gastroschisis is the most common congenital abdominal wall defect with a rising prevalence. Infants with gastroschisis are at risk for multiple complications, leading to a potential increased risk for hospital readmission after discharge. We aimed to find the frequency and factors associated with an increased risk of readmission.

METHODS

A retrospective analysis of infants born with gastroschisis between 2013 and 2019 who received initial surgical intervention and follow-up care in the Children's Wisconsin health system was performed. The primary outcome was the frequency of hospital readmission within 1 year of discharge. We also compared maternal and infant clinical and demographic variables between those readmitted for reasons related to gastroschisis, and those readmitted for other reasons or not readmitted.

RESULTS

Forty of 90 (44%) infants born with gastroschisis were readmitted within 1-year of the initial discharge date, with 33 (37%) of the 90 infants being readmitted due to reasons directly related to gastroschisis. The presence of a feeding tube (p < 0.0001), a central line at discharge (p = 0.007), complex gastroschisis (p = 0.045), conjugated hyperbilirubinemia (p = 0.035), and the number of operations during the initial hospitalization (p = 0.044) were associated with readmission. Maternal race/ethnicity was the only maternal variable associated with readmission, with Black race being less likely to be readmitted (p = 0.003). Those who were readmitted were also more likely to be seen in outpatient clinics and utilize emergency healthcare resources. There was no statistically significant difference in readmission based on socioeconomic factors (all p > 0.084).

CONCLUSION

Infants with gastroschisis have a high hospital readmission rate, which is associated with a variety of risk factors including complex gastroschisis, multiple operations, and the presence of a feeding tube or central line at discharge. Improved awareness of these risk factors may help stratify patients in need of increased parental counseling and additional follow-up.

Abdominal Wall Defects: A Review of Current Practice Guidelines

The 2 most common congenital abdominal wall defects are gastroschisis and omphalocele. Gastroschisis is a defect in the abdominal wall with exposed abdominal contents. Mortality rates are low but lengths of stay are often prolonged by bowel dysmotility and other intestinal abnormalities in complicated cases. Omphalocele is a defect through the umbilical cord with herniated abdominal contents covered by a sac. It is associated with other genetic abnormalities and other anomalies that can lead to significant morbidity and mortality. Prenatal diagnosis in both conditions allows for improved prenatal consultation and coordinated perinatal care to improve clinical outcomes.

Being small for gestational age is not an independent risk factor for mortality in neonates with congenital diaphragmatic hernia: a multicenter study

BACKGROUND

Congenital diaphragmatic hernia (CDH) accounts for 8% of all major congenital anomalies. Neonates who are small for gestational age (SGA) generally have a poorer prognosis. We sought to identify risk factors and variables associated with outcomes in neonates with CDH who are SGA in comparison to neonates who are appropriate for gestational age (AGA).

METHODS

We used the multicenter Diaphragmatic Hernia Research & Exploration Advancing Molecular Science (DHREAMS) study to include neonates enrolled from 2005 to 2019. Chi-squared or Fisher's exact tests were used to compare categorical variables and t tests or Wilcoxon rank sum for continuous variables. Cox model analyzed time to event outcomes and logistic regression analyzed binary outcomes.

RESULTS

589 neonates were examined. Ninety were SGA (15.3%). SGA patients were more likely to be female (p = 0.003), have a left sided CDH (p = 0.05), have additional congenital anomalies and be diagnosed with a genetic syndrome (p < 0.001). On initial single-variable analysis, SGA correlated with higher frequency of death prior to discharge (p < 0.001) and supplemental oxygen requirement at 28 days (p = 0.005). Twice as many SGA patients died before repair (12.2% vs 6.4%, p = 0.04). Using unadjusted Cox model, the risk of death prior to discharge among SGA patients was 1.57 times the risk for AGA patients (p = 0.029). There was no correlation between SGA and need for ECMO, pulmonary hypertensive medication at discharge or oxygen at discharge. After adjusting for confounding variables, SGA no longer correlated with mortality prior to discharge or incidence of unrepaired defects but remained significant for oxygen requirement at 28 days (p = 0.03).

CONCLUSION

Infants with CDH who are SGA have worse survival and poorer lung function than AGA infants. However, the outcome of SGA neonates is impacted by other factors including gestational age, genetic syndromes, and particularly congenital anomalies that contribute heavily to their poorer prognosis.

Controversies in Fetal Surgery: Prenatal Repair of Myelomeningocele in the Modern Era

Fetal surgery is a constantly evolving field that showed noticeable progress with the treatment of myelomeningocele (MMC) using prenatal repair. Despite this success, there are ongoing questions regarding the optimal approach for fetal myelomeningocele repair, as well as which patients are eligible. Expansion of the inclusion and exclusion criteria is an important ongoing area of study for myelomeningocele including the recent Management of Myelomeningocele Plus trial. The significant personal and financial burden required of families seeking treatment has likely limited its accessibility to the general population.

Placental Location in Maternal-Fetal Surgery for Myelomeningocele

INTRODUCTION

Uterine incision based on placental location in open maternal-fetal surgery (OMFS) has never been evaluated in regards to maternal or fetal outcomes.

OBJECTIVE

To investigate whether an anterior placenta was associated with increased rates of intraoperative, perioperative, antepartum, obstetric, or neonatal complications in mothers and babies who underwent OMFS for myelomeningocele (fMMC) closure.

METHODS

Data from the international multi-center prospective registry of patients who underwent OMFS for fMMC closure (fMMC Consortium Registry, 12/15/2010-7/31/2019) was used to compare fetal and maternal outcomes between anterior and posterior placental locations.

RESULTS

Placental location for 623 patients was evenly distributed between anterior (51%) or posterior (49%). Intraoperative fetal bradycardia (8.3% vs 3.0%, p=0.005) and performance of fetal resuscitation (3.6% vs 1.0%, p=0.034) occurred more frequently in cases with an anterior placenta when compared to those with a posterior placenta. Obstetric outcomes including membrane separation, placental abruption, and spontaneous rupture of membranes were not different among the two groups. However, thinning of the hysterotomy site (27.7% vs 17.7%, p=0.008) occurred more frequently in cases of anterior placenta. Gestational age at delivery (p=0.583) and length of stay in the neonatal intensive care unit (p=0.655) were similar between the two groups. Fetal incision dehiscence and wound revision were not significantly different between groups. Critical clinical outcomes including fetal demise, perinatal death, and neonatal death were all infrequent occurrences and not associated with placental location.

CONCLUSIONS

Anterior placental location is associated with increased risk of intraoperative fetal resuscitation and increased thinning at the hysterotomy closure site. Individual institutional experiences may have varied but the aggregate data from the fMMC Consortium did not show a significant impact on the gestational age at delivery or maternal or fetal clinical outcomes.

Insights from barium variability in a Siderastrea siderea coral in the northwestern Gulf of Mexico

Coral Ba/Ca is a proxy for seawater barium concentration that varies with upwelling, terrigenous input, and marine productivity whereas coral Sr/Ca varies with temperature. We examine monthly coral Ba/Ca and Sr/Ca before and during offshore oil exploration in a Siderastrea siderea coral from West Flower Garden Bank located on the continental shelf edge in the Gulf of Mexico. Coral Ba/Ca variations lack pulses driven by upwelling or river outflow and are not in sync with coral Sr/Ca that exhibit a different seasonal pattern. Seasonal variations in chlorophyll-a concentration negatively correlate with coral Ba/Ca explaining 25% of that variability. A significant increase in mean coral Ba/Ca of 1.76 μmol/mol between 1931-1944 and 1976-2004 corresponds to the increase in the United States barite production and consumption primarily used in offshore oil drilling, which escalated in the 1970s, suggesting oil drilling operations are increasing seawater Ba concentration in the Gulf of Mexico.

Rare and de novo variants in 827 congenital diaphragmatic hernia probands implicate LONP1 as candidate risk gene

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly that is often accompanied by other anomalies. Although the role of genetics in the pathogenesis of CDH has been established, only a small number of disease-associated genes have been identified. To further investigate the genetics of CDH, we analyzed de novo coding variants in 827 proband-parent trios and confirmed an overall significant enrichment of damaging de novo variants, especially in constrained genes. We identified LONP1 (lon peptidase 1, mitochondrial) and ALYREF (Aly/REF export factor) as candidate CDH-associated genes on the basis of de novo variants at a false discovery rate below 0.05. We also performed ultra-rare variant association analyses in 748 affected individuals and 11,220 ancestry-matched population control individuals and identified LONP1 as a risk gene contributing to CDH through both de novo and ultra-rare inherited largely heterozygous variants clustered in the core of the domains and segregating with CDH in affected familial individuals. Approximately 3% of our CDH cohort who are heterozygous with ultra-rare predicted damaging variants in LONP1 have a range of clinical phenotypes, including other anomalies in some individuals and higher mortality and requirement for extracorporeal membrane oxygenation. Mice with lung epithelium-specific deletion of Lonp1 die immediately after birth, most likely because of the observed severe reduction of lung growth, a known contributor to the high mortality in humans. Our findings of both de novo and inherited rare variants in the same gene may have implications in the design and analysis for other genetic studies of congenital anomalies.

A Novel Surgical Treatment for Pediatric Fulminant Clostridium Difficile Colitis

Pediatric patients rarely present with severe, complicated Clostridium difficile colitis. The medical and surgical management of pediatric patients is primarily based on evidence from adult populations, in which standard therapy often includes subtotal colectomy and end ileostomy. New evidence in adults suggests that a diverting loop ileostomy and colonic lavage is an effective alternative for the management of refractory severe, complicated C difficile colitis. We report the case of a 15-year-old female patient who developed severe, complicated C difficile colitis. After failing medical management, she underwent a diverting loop ileostomy with antegrade colonic lavage and recovered uneventfully. There is limited literature on the medical management of C difficile –associated disease in pediatric patients and even less information on the medical or surgical management of severe, complicated C difficile colitis in pediatrics. Diverting loop ileostomy and colonic lavage should be considered as an alternative to subtotal colectomy and end ileostomy in a pediatric patient with severe, complicated C difficile colitis.

Risk factors for perioperative hypothermia and infectious outcomes in gastroschisis patients

INTRODUCTION

Prior data suggest that infants with gastroschisis are at high risk for hypothermia and infectious complications (ICs). This study evaluated the associations between perioperative hypothermia (PH) and ICs in gastroschisis using a multi-institutional cohort.

METHODS

Retrospective review of infants with gastroschisis who underwent abdominal closure from 2013-2017 was performed at 7 children's hospitals. Any-IC and surgical site infection (SSI) were stratified against the presence or absence of PH, and perioperative characteristics associated with PH and SSI were determined using multivariable logistic regression.

RESULTS

Of 256 gastroschisis neonates, 42% developed PH, with 18% classified as mild hypothermia (35.5-35.9 °C), 10.5% as moderate (35.0-35.4 °C), and 13% severe (<35 °C). There were 82 (32%) ICs with 50 (19.5%) being SSIs. No associations between PH and any-IC (p = 0.7) or SSI (p = 0.98) were found. Pulmonary comorbidities (odds ratio (OR)=3.76, 95%CI:1.42-10, p = 0.008) and primary closure (OR=0.21, 95%CI:0.12-0.39, p<0.001) were associated with PH, while silo placement (OR=2.62, 95%CI:1.1-6.3, p = 0.03) and prosthetic patch (OR=3.42, 95%CI:1.4-8.3, p = 0.007) were associated with SSI on multivariable logistic regression.

CONCLUSIONS

Primary abdominal closure and pulmonary comorbidities are associated with PH in gastroschisis, however PH was not associated with increased risk of ICs. Independent risk factors for SSI include silo placement and prosthetic patch closure.

Epithelioid hemangioendothelioma, an ultra-rare cancer: a consensus paper from the community of experts

Epithelioid hemangioendothelioma (EHE) is an ultra-rare, translocated, vascular sarcoma. EHE clinical behavior is variable, ranging from that of a low-grade malignancy to that of a high-grade sarcoma and it is marked by a high propensity for systemic involvement. No active systemic agents are currently approved specifically for EHE, which is typically refractory to the antitumor drugs used in sarcomas. The degree of uncertainty in selecting the most appropriate therapy for EHE patients and the lack of guidelines on the clinical management of the disease make the adoption of new treatments inconsistent across the world, resulting in suboptimal outcomes for many EHE patients. To address the shortcoming, a global consensus meeting was organized in December 2020 under the umbrella of the European Society for Medical Oncology (ESMO) involving >80 experts from several disciplines from Europe, North America and Asia, together with a patient representative from the EHE Group, a global, disease-specific patient advocacy group, and Sarcoma Patient EuroNet (SPAEN). The meeting was aimed at defining, by consensus, evidence-based best practices for the optimal approach to primary and metastatic EHE. The consensus achieved during that meeting is the subject of the present publication.

•

This consensus paper provides key recommendations on the management of epithelioid hemangioendothelioma (EHE).

•

Recommendations followed a consensus meeting between experts and a representative of the EHE advocacy group and SPAEN.

•

Authorship includes a multidisciplinary group of experts from different institutions from Europe, North America and Asia.

Abdominal wall defects

Abdominal wall defects are common congenital anomalies with the most frequent being gastroschisis and omphalocele. Though both are the result of errors during embryologic development of the fetal abdominal wall, gastroschisis and omphalocele represent unique disorders that have different clinical sequelae. Gastroschisis is generally a solitary anomaly with postnatal outcomes related to the underlying integrity of the prolapsed bowel. In contrast, omphalocele is frequently associated with other structural anomalies or genetic syndromes that contribute more to postnatal outcomes than the omphalocele defect itself. Despite their embryological differences, both gastroschisis and omphalocele represent anomalies of fetal development that benefit from multidisciplinary and translational approaches to care, both pre- and postnatally. While definitive management of abdominal wall defects currently remains in the postnatal realm, advancements in prenatal diagnostics and therapies may one day change that. This review focuses on recent advancements, novel techniques, and current controversies related to the prenatal diagnosis and management of gastroschisis and omphalocele.

Likely damaging de novo variants in congenital diaphragmatic hernia patients are associated with worse clinical outcomes

Purpose

Congenital diaphragmatic hernia (CDH) is associated with significant mortality and long-term morbidity in some but not all individuals. We hypothesize monogenic factors that cause CDH are likely to have pleiotropic effects and be associated with worse clinical outcomes.

Methods

We enrolled and prospectively followed 647 newborns with CDH and performed genomic sequencing on 462 trios to identify de novo variants. We grouped cases into those with and without likely damaging (LD) variants and systematically assessed CDH clinical outcomes between the genetic groups.

Results

Complex cases with additional congenital anomalies had higher mortality than isolated cases (P=8×10⁻⁶). Isolated cases with LD variants had similar mortality to complex cases and much higher mortality than isolated cases without LD (P=3×10⁻³). The trend was similar with pulmonary hypertension at 1 month. Cases with LD variants had an estimated 12–17 points lower scores on neurodevelopmental assessments at 2 years compared to cases without LD variants, and this difference is similar in isolated and complex cases.

Conclusion

We found that the LD genetic variants are associated with higher mortality, worse pulmonary hypertension, and worse neurodevelopment outcomes compared to non-LD variants. Our results have important implications for prognosis, potential intervention and long-term follow up for children with CDH.

Comparative outcomes of right versus left congenital diaphragmatic hernia: A multicenter analysis

BACKGROUND

Congenital diaphragmatic hernia (CDH) occurs in 1 out of 2500-3000 live births. Right-sided CDHs (R-CDHs) comprise 25% of all CDH cases, and data are conflicting on outcomes of these patients. The aim of our study was to compare outcomes in patients with right versus left CDH (L-CDH).

METHODS

We analyzed a multicenter prospectively enrolled database to compare baseline characteristics and outcomes of neonates enrolled from January 2005 to January 2019 with R-CDH vs. L-CDH.

RESULTS

A total of 588, 495 L-CDH, and 93 R-CDH patients with CDH were analyzed. L-CDHs were more frequently diagnosed prenatally (p=0.011). Lung-to-head ratio was similar in both cohorts. R-CDHs had a lower frequency of primary repair (p=0.022) and a higher frequency of need for oxygen at discharge (p=0.013). However, in a multivariate analysis, need for oxygen at discharge was no longer significantly different. There were no differences in long-term neurodevelopmental outcomes assessed at two year follow up. There was no difference in mortality, need for ECMO, pulmonary hypertension, or hernia recurrence.

CONCLUSION

In this large series comparing R to L-CDH patients, we found no significant difference in mortality, use of ECMO, or pulmonary complications. Our study supports prior studies that R-CDHs are relatively larger and more often require a patch or muscle flap for repair.

TYPE OF STUDY

Prognosis study LEVEL OF EVIDENCE: Level II.

Dynamic discriminant model for predicting respiratory distress at birth based on mass volume ratio in fetuses with congenital lung malformation

OBJECTIVES

The congenital lung malformation volume ratio (CVR) is a prenatal ultrasound measurement that parameterizes congenital lung malformation (CLM) size. The aims of this study were to use serial measurements to create estimated growth curves of fetal CVR for asymptomatic and symptomatic neonates with CLM and to investigate whether a discriminant prognostic model based on these measurements could predict accurately which fetuses with CLM will require invasive respiratory support at delivery and should therefore be delivered at a tertiary-care facility.

METHODS

This was a retrospective study of fetuses diagnosed prenatally with CLM at three tertiary-care children's hospitals between 2009 and 2016. Those with two or more sonographic measurements of CVR were included. Serial fetal CVR measurements were used to create estimated growth curves for neonates with and those without respiratory symptoms at delivery, defined as requiring invasive respiratory support for the first 24 h after delivery. A discriminant model based on serial CVR measurements was used to calculate the dynamic probability of the need for invasive respiratory support. The performance of this model overall and in preterm and term neonates was compared with those using maximum CVR thresholds of 1.0 and 1.6.

RESULTS

Of the 147 neonates meeting the inclusion criteria, 16 (10.9%) required postnatal invasive respiratory support. The estimated CVR growth curve models showed different growth trajectories for asymptomatic and symptomatic neonates, with significantly higher CVR in symptomatic neonates, and values peaking late in the second trimester at around 25 weeks' gestation in asymptomatic neonates. All prognostic methods had high accuracy for the prediction of the need for invasive respiratory support in term neonates, but the discriminant model had the best performance overall (area under the receiver-operating characteristics curve (AUC) = 0.88) and in the preterm population (AUC = 0.85).

CONCLUSIONS

The estimated CVR growth curves showed different growth patterns in asymptomatic and symptomatic neonates with CLM. The dynamic discriminant model performed well overall and particularly in neonates that were carried to term. Development of an externally validated clinical tool based on this analysis could be useful in determining the site of delivery for fetuses with CLM. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Ex utero intrapartum treatment (EXIT) procedures

Ex Utero Intrapartum Treatment (EXIT) is a technique developed to safely and efficiently establish cardiopulmonary support at delivery while maintaining placental bypass. Indications for the EXIT approach are expanding and currently include EXIT-to-airway, EXIT-to-resection, EXIT-to-extracorporeal membrane oxygenation (ECMO), and EXIT-to-separation of conjoined twins. The EXIT technique involves planned partial delivery of the fetus via hysterotomy while maintaining uterine relaxation and placental support, allowing for the establishment of neonatal cardiopulmonary stability in a controlled manner. Fetal interventions performed during EXIT can include endotracheal intubation, tracheostomy, mass excision, removal of a temporary tracheal occlusive device, ECMO cannulation, and others. The most important aspect of an EXIT procedure is the formation of a multi-disciplinary team with broad expertise in fetal intervention to collaborate throughout the pre, intra, and post-partum periods. This chapter reviews the prenatal workup, decision making, surgical indications, and operative considerations associated with EXIT procedures.

Subsequent pregnancy outcomes after open maternal-fetal surgery for myelomeningocele

BACKGROUND

Open maternal-fetal surgery for fetal myelomeningocele results in reduction in neonatal morbidity related to spina bifida but may be associated with fetal, neonatal, and maternal complications in subsequent pregnancies.

OBJECTIVE

The objective of this study was to ascertain obstetric risk in subsequent pregnancies after open maternal-fetal surgery for fetal myelomeningocele closure.

STUDY DESIGN

An international multicenter prospective observational registry created to track and report maternal, obstetric, fetal/neonatal, and subsequent pregnancy outcomes following open maternal-fetal surgery for fetal myelomeningocele was evaluated for subsequent pregnancy outcome variables. Institutional Review Board approval was obtained for the registry.

RESULTS

From 693 cases of open maternal-fetal surgery for fetal myelomeningocele closure entered into the registry, 77 subsequent pregnancies in 60 women were identified. The overall live birth rate was 96.2%, with 52 pregnancies delivering beyond 20 weeks gestational age and median gestational age at delivery of 37 (36.3-37.1) weeks. The uterine rupture rate was 9.6% (n = 5), resulting in 2 fetal deaths. Maternal transfusion was required in 4 patients (7.7%).

CONCLUSION

The risk of uterine rupture or dehiscence in subsequent pregnancies with associated fetal morbidity after open maternal-fetal surgery is significant, but is similar to that reported for subsequent pregnancies after classical cesarean deliveries. Future pregnancy considerations should be included in initial counseling for women contemplating open maternal-fetal surgery.

De novo variants in congenital diaphragmatic hernia identify MYRF as a new syndrome and reveal genetic overlaps with other developmental disorders

Congenital diaphragmatic hernia (CDH) is a severe birth defect that is often accompanied by other congenital anomalies. Previous exome sequencing studies for CDH have supported a role of de novo damaging variants but did not identify any recurrently mutated genes. To investigate further the genetics of CDH, we analyzed de novo coding variants in 362 proband-parent trios including 271 new trios reported in this study. We identified four unrelated individuals with damaging de novo variants in MYRF (P = 5.3x10(-8)), including one likely gene-disrupting (LGD) and three deleterious missense (D-mis) variants. Eight additional individuals with de novo LGD or missense variants were identified from our other genetic studies or from the literature. Common phenotypes of MYRF de novo variant carriers include CDH, congenital heart disease and genitourinary abnormalities, suggesting that it represents a novel syndrome. MYRF is a membrane associated transcriptional factor highly expressed in developing diaphragm and is depleted of LGD variants in the general population. All de novo missense variants aggregated in two functional protein domains. Analyzing the transcriptome of patient-derived diaphragm fibroblast cells suggest that disease associated variants abolish the transcription factor activity. Furthermore, we showed that the remaining genes with damaging variants in CDH significantly overlap with genes implicated in other developmental disorders. Gene expression patterns and patient phenotypes support pleiotropic effects of damaging variants in these genes on CDH and other developmental disorders. Finally, functional enrichment analysis implicates the disruption of regulation of gene expression, kinase activities, intra-cellular signaling, and cytoskeleton organization as pathogenic mechanisms in CDH.

Meconium-stained amniotic fluid as a predictor of poor outcomes in gastroschisis

OBJECTIVE

The aim of this study was to determine if meconium-stained amniotic fluid (MSAF) was associated with neonatal outcomes in gastroschisis.

STUDY DESIGN

A retrospective chart review of gastroschisis patients from 2000 to 2014 at a single, tertiary institution was performed. Statistical analysis was performed with Fisher exact test, Welch's t-test, logistic regression and/or linear regression with significance at p < 0.05.

RESULTS

Sixty-four of 135 (47.4%) gastroschisis patients had MSAF. On univariate analysis, patients with MSAF were more likely to require staged closure (30 (46.9%) vs. 18(25.4%), p = 0.012), had more ventilator days (8.9 ± 11.1 vs. 5.3 ± 6.3, p = 0.021) and longer times to commence enteral feeds (24.9 ± 21.7 vs. 18.5 ± 14.5, p = 0.045). However, multi-variate regression analysis controlling for the type of closure, showed that delayed closure, but not MSAF, was associated with worse outcomes.

CONCLUSIONS

In gastroschisis patients, MSAF is associated with delayed closure but is not associated with outcomes independent of closure type. This association may be because of the matting of the bowel or increased intestinal damage. The MSAF status will aid in setting expectations for parents during their initial NICU stay and further investigation is warranted.

TYPE OF STUDY

Clinical Research Paper Level of evidence: III.

Is isomerism a risk factor for intestinal volvulus?

INTRODUCTION

Isomerism, or heterotaxy syndrome, affects many organ systems anatomically and functionally. Intestinal malrotation is common in patients with isomerism. Despite a low reported risk of volvulus, some physicians perform routine screening and prophylactic Ladd procedures on asymptomatic patients with isomerism who are found to have intestinal malrotation. The primary aim of this study was to determine if isomerism is an independent risk factor for volvulus.

METHODS

Kid's Inpatient Database data from 1997 to 2012 was utilized for this study. Characteristics of admissions with and without isomerism were compared with a particular focus on intestinal malrotation, volvulus, and Ladd procedure. A logistic regression was conducted to determine independent risk factors for volvulus with respect to isomerism.

RESULTS

15,962,403 inpatient admissions were included in the analysis, of which 7970 (0.05%) patients had isomerism, and 6 patients (0.1%) developed volvulus. Isomerism was associated with a 52-fold increase in the odds of intestinal malrotation by univariate analysis. Of 251 with isomerism and intestinal malrotation, only 2.4% experienced volvulus. Logistic regression demonstrated that isomerism was not an independent risk factor for volvulus.

CONCLUSION

Isomerism is associated with an increased risk of intestinal malrotation but is not an independent risk factor for volvulus.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level III.

National Practice Patterns for Prenatal Monitoring in Gastroschisis: Gastroschisis Outcomes of Delivery (GOOD) Provider Survey

BACKGROUND

Gastroschisis is an abdominal wall defect with increasing incidence. Given the lack of surveillance guidelines among maternal-fetal medicine (MFM) specialists, this study describes current practices in gastroschisis management.

MATERIALS AND METHODS

An online survey was administered to MFM specialists from institutions affiliated with the North American Fetal Therapy Network (NAFTNet). Questions focused on surveillance timing, testing, findings that changed clinical management, and delivery plan.

RESULTS

Responses were obtained from 29/29 (100%) NAFTNet centers, comprising 143/371 (39%) providers. The majority had a regimen for antenatal surveillance in patients with stable gastroschisis (94%; 134/141). Antenatal testing began at 32 weeks for 68% (89/131) of MFM specialists. The nonstress test (55%; 72/129), biophysical profile (50%; 63/126), and amniotic fluid index (64%; 84/131) were used weekly. Estimated fetal weight (EFW) was performed monthly by 79% (103/131) of providers. At 28 weeks, abnormal EFW (77%; 97/126) and Doppler ultrasound (78%; 99/127) most frequently altered management. In stable gastroschisis, 43% (60/140) of providers delivered at 37 weeks, and 29% (40/ 140) at 39 weeks.

DISCUSSION

Gastroschisis management differs among NAFTNet centers, although the majority initiate surveillance at 32 weeks. Timing of delivery still requires consensus. Prospective studies are necessary to further optimize practice guidelines and patient care.

A phase II study of a human anti-PDGFRα monoclonal antibody (olaratumab, IMC-3G3) in previously treated patients with metastatic gastrointestinal stromal tumors

Background

This study evaluated tumor response to olaratumab (an anti-PDGFRα monoclonal antibody) in previously treated patients with metastatic gastrointestinal stromal tumor (GIST) with or without PDGFRα mutations (cohorts 1 and 2, respectively).

Patients and methods

Patients received olaratumab 20 mg/kg intravenously every 14 days until disease progression, death, or intolerable toxicity occurred. Outcome measures were 12-week tumor response, progression-free survival (PFS), overall survival (OS), and safety.

Results

Of 30 patients enrolled, 21 patients received ≥1 dose of olaratumab. In the evaluable population (cohort 1, n = 6; cohort 2, n = 14), no complete response (CR) or partial response (PR) was observed. Stable disease (SD) was observed in 3 patients (50.0%) in cohort 1 and 2 patients (14.3%) in cohort 2. Progressive disease (PD) was observed in 3 patients (50.0%) in cohort 1 and 12 patients (85.7%) in cohort 2. The 12-week clinical benefit rate (CR + PR + SD) (90% CI) was 50.0% (15.3–84.7%) in cohort 1 and 14.3% (2.6–38.5%) in cohort 2. SD lasted beyond 12 weeks in 5 patients (cohort 1, n = 3; cohort 2, n = 2). Median PFS (90% CI) was 32.1 (5.0–35.9) weeks in cohort 1 and 6.1 (5.7–6.3) weeks in cohort 2. Median OS was not reached in cohort 1 and was 24.9 (14.4–49.1) weeks in cohort 2. All patients in cohort 1 and 9 (64.3%) in cohort 2 experienced an olaratumab-related adverse event (AE), most commonly fatigue (38.1%), nausea (19.0%), and peripheral edema (14.3%). Two grade ≥3 olaratumab-related events were reported (cohort 1, syncope; cohort 2, hypertension).

Conclusions

Olaratumab had an acceptable AE profile in patients with GIST. While there was no apparent effect on PFS in patients without PDGFRα mutations, patients with PDGFRα-mutant GIST (all with D842V mutations) treated with olaratumab had longer disease control compared with historical data for this genotype.

ClinicalTrials.gov Identifier

NCT01316263.

A definition of gentle ventilation in congenital diaphragmatic hernia: a survey of neonatologists and pediatric surgeons

Ventilation practices have changed significantly since the initial reports in the mid 1980 of successful use of permissive hypercapnia and spontaneous ventilation [often called gentle ventilation (GV)] in infants with congenital diaphragmatic hernia (CDH). However, there has been little standardization of these practices or of the physiologic limits that define GV. We sought to ascertain among Diaphragmatic Hernia Research and Exploration; Advancing Molecular Science (DHREAMS) centers' GV practices in the neonatal management of CDH. Pediatric surgeons and neonatologists from DHREAMS centers completed an online survey on GV practices in infants with CDH. The survey gathered data on how individuals defined GV including ventilator settings, blood gas parameters and other factors of respiratory management. A total of 87 respondents, from 12 DHREAMS centers completed the survey for an individual response rate of 53% and a 92% center response rate. Approximately 99% of the respondents defined GV as accepting higher carbon dioxide (PCO2) and 60% of the respondents also defined GV as accepting a lower pH. There was less consensus about the use of sedation and neuromuscular blocking agents in GV, both within and across the centers. Acceptable pH and PCO2 levels are broader than the goal ranges. Despite a lack of formal standardization, the results suggest that GV practice is consistently defined as the use of permissive hypercapnia with mild respiratory acidosis and less consistently with the use of sedation and neuromuscular blocking agents. GV is the reported practice of surveyed neonatologists and pediatric surgeons in the respiratory management of infants with CDH.

The significance of organ prolapse in gastroschisis

PURPOSE

The aim of this study was to evaluate the incidence and importance of organ prolapse (stomach, bladder, reproductive organs) in gastroschisis.

METHODS

This is a retrospective review of gastroschisis patients from 2000 to 2014 at a single tertiary institution. Statistical analysis was performed using a chi-square test, Student's t test, log-rank test, or Cox regression analysis models. All tests were conducted as two-tailed tests, and p-values <0.05 were considered statistically significant.

RESULTS

One hundred seventy-one gastroschisis patients were identified. Sixty-nine (40.6%) had at least one prolapsed organ besides bowel. The most commonly prolapsed organs were stomach (n=45, 26.3%), reproductive organs (n=34, 19.9%), and bladder (n=15, 8.8%). Patients with prolapsed organs were more likely to have simple gastroschisis with significant decreases in the rate of atresia and necrosis/perforation. They progressed to earlier enteral feeds, discontinuation of parenteral nutrition, and discharge. Likewise, these patients were less likely to have complications such as central line infections, sepsis, and short gut syndrome.

CONCLUSIONS

Gastroschisis is typically described as isolated bowel herniation, but a large portion have prolapse of other organs. Prolapsed organs are associated with simple gastroschisis, and improved outcomes most likely due to a larger fascial defect. This may be useful for prenatal and postnatal counseling of families.

TYPE OF STUDY

Case Control/Retrospective Comparative Study.

LEVEL OF EVIDENCE

Level III.

Outcomes of gastroschisis early delivery: A systematic review and meta-analysis

BACKGROUND/PURPOSE

Elective preterm delivery (EPD) of a fetus with gastroschisis may prevent demise and ameliorate intestinal injury. While the literature on optimal timing of delivery varies, we hypothesize that a potential benefit may be found with EPD.

METHODS

A meta-analysis of publications describing timing of delivery in gastroschisis from 1/1990 to 8/2016 was performed, including studies where either elective preterm delivery (group 1, G1) or preterm gestational age (GA) (group 2, G2) were evaluated against respective comparators. The following outcomes were analyzed: total parenteral nutrition (TPN), first enteral feeding (FF), length of stay, ventilator days, fetal demise, complex gastroschisis, sepsis, and death.

RESULTS

Eighteen studies describing 1430 gastroschisis patients were identified. G1 studies found less sepsis (p<0.01), fewer days to FF (p=0.03), and 11days less of TPN (p=0.07) in the preterm cohort. Comparatively, G2 studies showed less days to FF in term GA (p=0.02).Whereas G1 BWs were similar, G2 preterm had a significantly lower BW compared to controls (p=0.001).

CONCLUSIONS

Elective preterm delivery appears favorable with respect to feeding and sepsis. However, benefits are lost when age is used as a surrogate of EPD. A randomized, prospective, multi-institutional trial is necessary to delineate whether EPD is advantageous to neonates with gastroschisis.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

Infectious outcomes of gastroschisis patients with intraoperative hypothermia

BACKGROUND

Perioperative hypothermia decreases nutrient and oxygen delivery to tissues and, in adult studies, increases the risk of infectious complications (ICs). Gastroschisis (GS) places newborns at risk for hypothermia by nature of exposed viscera and excessive heat loss. Although hypothermia is a known cause of mortality in GS, the rate of ICs in this at-risk cohort has not yet been delineated.

MATERIALS AND METHODS

A retrospective cohort study was performed at our single tertiary-referral hospital, evaluating patient and operative characteristics of all GS infants who underwent operative closure. Intraoperative temperatures were recorded, defining hypothermia as mild (35.5°C-35.9°C), moderate (35.0°C-35.4°C), or severe (<35°C). Temperature nadirs, procedural and anesthesia duration were observed. The primary outcome was 30-d surgical site infections. Secondary measures included other ICs.

RESULTS

Among 43 GS neonates, 21 (48.8%) had intraoperative hypothermia, classified as mild in 2 (4.7%), moderate in 8 (18.6%), and severe in 11 (25.6%). Nineteen ICs occurred in 35.9% of patients, including 10 (23.3%) surgical site infections. There was no association between hypothermia and ICs. Patient and operative characteristics were similar between normothermic and hypothermic groups, except that normothermic infants were more likely to have silos placed with delayed closure than hypothermic patients (63.6% versus 23.8%, P = 0.01).

CONCLUSIONS

Infants with GS are at high risk for hypothermia and ICs, though newborns with silos were less subject to temperature lability. A multiinstitutional study with greater power is needed to further investigate the relationship between perioperative hypothermia and surgical ICs.

Effects of anticipated neonatal surgical intervention on maternal milk cytokine production

BACKGROUND

Maternal stress on neonatal outcomes of infants admitted to the NICU is incompletely understood. We previously demonstrated breast milk derived cytokines remain biologically active in the neonatal intestine. We hypothesized that the need for neonatal surgical intervention would be stimulus leading to maternal cytokine production thus affecting neonatal outcome.

METHODS

Discarded expressed breast milk (EBM) in the first 3weeks following delivery was analyzed for IL-23 and IL-10 by ELISA. Variables analyzed included: the need for a pediatric surgical procedure, the need for cardiac surgical procedure, no surgical interventions, and survival. All values are expressed as mean±SEM. Statistical analysis utilized Kruskal and Mann-Whitney test.

RESULTS

EBM from mothers whose infants required any surgical procedure (n=19) revealed significant elevation in IL-10 but not IL-23 compared to nonsurgical EBM (n=18). Subdivided by procedure type, there was no difference between those undergoing a cardiac (n=9) versus pediatric surgical (n=10) procedure in both IL-10 and IL-23. Mothers whose infants requiring surgical intervention or whose infants did not survive in the first 3weeks of life had elevation of IL-10.

CONCLUSION

Results suggest maternal stress impacts the cytokine profile of breast milk.

LEVEL OF EVIDENCE

Level III.

The risk of midgut volvulus in patients with abdominal wall defects: A multi-institutional study

BACKGROUND

The management of malrotation in patients with congenital abdominal wall defects has varied among surgeons. We were interested in investigating the risk of midgut volvulus in patients with gastroschisis and omphalocele to help determine if these patients may benefit from undergoing a Ladd procedure.

METHODS

A retrospective chart review was performed for all patients managed at three institutions born between 1/1/2000 and 12/31/2008 with a diagnosis of gastroschisis or omphalocele. Patient charts were reviewed through 12/31/2012 for occurrence of midgut volvulus or need for second laparotomy.

RESULTS

Of the 414 patients identified with abdominal wall defects, 299 patients (72%) had gastroschisis, and 115 patients (28%) had omphalocele. The mean gestational age at birth was 36.1±2.3weeks, and the mean birth weight was 2.57±0.7kg. There were a total of 8 (1.9%) cases of midgut volvulus: 3 (1.0%) patients with gastroschisis compared to 5 patients (4.4%) with omphalocele (p=0.04).

CONCLUSIONS

Patients with omphalocele have a greater risk of developing midgut volvulus, and a Ladd procedure should be considered during definitive repair to mitigate these risks.

LEVEL OF EVIDENCE

III; retrospective comparative study.

Long-term follow-up results of the multicenter phase II trial of regorafenib in patients with metastatic and/or unresectable GI stromal tumor after failure of standard tyrosine kinase inhibitor therapy

BACKGROUND

This investigator-initiated trial provided the justification for the phase III GRID study resulting in worldwide regulatory approval of regorafenib as a third-line therapy for patients with metastatic gastrointestinal stromal tumors (GIST). We report the genotype analyses, long-term safety, and activity results from this initial trial of regorafenib in GIST.

PATIENTS AND METHODS

The trial was conducted between February 2010 and January 2014, among adult patients with metastatic GIST, after failure of at least imatinib and sunitinib. Patients received regorafenib orally, 160 mg once daily, days 1-21 of a 28-day cycle. Clinical benefit rate (CBR), defined as complete or partial response (PR), or stable disease lasting ≥16 weeks per RECIST 1.1, progression-free survival (PFS), overall survival (OS), long-term safety data, and metabolic response by functional imaging were assessed.

RESULTS

Thirty-three patients received at least one dose of regorafenib. The median follow-up was 41 months. CBR was documented in 25 of 33 patients [76%; 95% confidence interval (CI) 58% to 89%], including six PRs. The median PFS was 13.2 months (95% CI 9.2-18.3 months) including four patients who remained progression-free at study closure, each achieving clinical benefit for more than 3 years (range 36.8-43.5 months). The median OS was 25 months (95% CI 13.2-39.1 months). Patients whose tumors harbored a KIT exon 11 mutation demonstrated the longest median PFS (13.4 months), whereas patients with KIT/PDGFRA wild-type, non-SDH-deficient tumors experienced a median 1.6 months PFS (P < 0.0001). Long-term safety profile is consistent with previous reports; hand-foot skin reaction and hypertension were the most common reasons for dose reduction. Notably, regorafenib induced objective responses and durable benefit in SDH-deficient GIST.

CONCLUSIONS

Long-term follow-up of patients with metastatic GIST treated with regorafenib suggests particular benefit among patients with primary KIT exon 11 mutations and those with SDH-deficient GIST. Dose modifications are frequently required to manage treatment-related toxicities.

CLINICAL TRIAL NUMBER

NCT01068769.

Central Venous Access in the Pediatric Population With Emphasis on Complications and Prevention Strategies

Central venous catheters are often necessary in the pediatric population. Access may be challenging, and each vessel presents its own unique set of risks and complications. Central venous catheterization is useful for hemodynamic monitoring, rapid fluid infusion, and administration of hyperosmolar medications, including vasopressors, antibiotics, chemotherapy, and parenteral nutrition. Recent advances have improved the catheters used as well as techniques for insertion. A serious complication of central access is infection, which is associated with morbidity, mortality, and significant financial costs. Reduction of catheter-related bloodstream infections is realized with use of ethanol locks, single lumens when appropriate, and prudent adherence to insertion and maintenance bundles. Ultrasound guidance used for central venous catheter placement improves accuracy of placement, reducing time and unsuccessful insertion and complication rates. Patients with central venous catheters are best served by multidisciplinary team involvement.

Can omphalocele ratio predict postnatal outcomes?

BACKGROUND

The clinical course of patients with omphalocele is challenging to predict. There is no standard method to characterize omphalocele size. Previous studies suggest that the ratio of abdominal circumference to omphalocele defect in-utero is indicative of postnatal outcomes. We hypothesize that omphalocele ratio correlates with outcomes of primary closure versus staged closure.

METHODS

A retrospective chart review of all neonates diagnosed with omphalocele from 2002 to 2013 with prenatal ultrasounds available (n=30) was conducted. Omphalocele ratio was defined as omphalocele diameter/abdominal circumference (OD/AC). Data collected included primary versus staged closure, time to full feeds, duration of mechanical ventilation, and length of stay (LOS). Long-term outcomes and quality of life were also reported.

RESULTS

ROC curve analysis generated optimal OD/AC ratio of 0.26. Twenty of 30 patients had a ratio less than this cutoff. Sixty percent (12/20) in the low-ratio group achieved primary closure versus zero (0/10) in the high-ratio group (p=0.001). Time on mechanical ventilation was 15.8 days (low-ratio) versus 79 days (high-ratio) (p=0.05). LOS was 33.8 days (low-ratio) versus 85.6 days (high-ratio) (p=0.119). PedsQL™ mean score was 85.5 ± 11.0 (n=20) at long-term follow-up. Readmission rates yielded no difference.

CONCLUSIONS

The omphalocele ratio is a promising predictor of postnatal outcomes.

Observation versus prophylactic Ladd procedure for asymptomatic intestinal rotational abnormalities in heterotaxy syndrome: A systematic review

BACKGROUND

The management of intestinal rotational abnormalities (IRA) in heterotaxy syndrome (HS) remains inconsistent. Because of the high incidence of malrotation in HS, screening of asymptomatic patients is standard of care in some institutions. The Ladd procedure is the treatment for malrotation, and has been reported to have high complication rates in HS patients.

METHODS

We performed a systematic review of publications describing IRA in pediatric HS patients from January 1993 to present. The incidence of volvulus on surgical exploration was determined. Perioperative and long-term outcomes were analyzed to determine complication and mortality rates.

RESULTS

Eleven retrospective studies describing 649 HS patients were identified. Of all patients with HS, 27% (176/649) underwent Ladd procedure. Only 1.2% (8/649) of HS patients included had volvulus. Postoperative complications occurred in 25 patients (14%), including a 10% incidence of small bowel obstruction. Perioperative and overall mortality rates after Ladd procedure were 3% and 21%, respectively. Six studies described mesenteric width, reporting 43% to have narrow mesentery.

CONCLUSION

The Ladd procedure is not without significant morbidity and mortality in heterotaxy patients. Further prospective studies should investigate predictors of mesenteric width to spare the unnecessary morbidity of surgery in patients who are at low risk for volvulus.

Use of cell-free fetal DNA in maternal plasma for noninvasive prenatal screening

Noninvasive prenatal testing (NIPT) using cell-free fetal (cfDNA) offers potential as a screening tool for fetal anomalies. All pregnant women should be offered prenatal screening and diagnostic testing based on current guidelines. Adoption of NIPT in high-risk pregnancies suggests a change in the standard of care for genetic screening; there are advantages to an accurate test with results available early in pregnancy. This accuracy decreases the overall number of invasive tests needed for diagnosis, subjecting fewer pregnancies to the risks of invasive procedures. Women undergoing NIPT need informed consent before testing and accurate, sensitive counseling after results are available.

MDCT features of succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumours

OBJECTIVE

To describe the multidetector CT (MDCT) features and metastatic pattern of succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumours (GISTs).

METHODS

In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study, we retrospectively identified 34 patients (20 females; mean age, 34 years; range, 12-59 years) with histopathology-confirmed SDH-deficient GIST, who were seen at our institution from 1999 through 2012. MDCT of primary tumour in 8 patients and follow-up imaging in all 34 patients over median follow-up of 106 months [interquartile range (IQR), 52-175 months] were reviewed by two radiologists in consensus. Clinical information was extracted from electronic medical records.

RESULTS

Primary tumour in all 34 patients was located in the stomach. Mean tumour size (n = 8) was 9.6 cm (range, 8-14 cm). Primary tumours were lobulated, variable in growth pattern, hypo- (1/8) to isodense (7/8) and similar in enhancement to the skeletal muscle. Two were multifocal, four of eight had necrosis and one of eight had haemorrhage. Tumour rupture with haemoperitoneum and tumour-bowel fistula was noted in one patient each. During follow-up, 12/34 patients developed tumour in surgical bed, and 28/34 patients developed metastases. Most common sites of metastases were the liver (24/34), peritoneum (20/34) and lymph nodes (18/34). Carney triad and Carney-Stratakis syndrome were noted in 5/34 and 1/34 patients, respectively. At the time of writing, six patients had deceased at a median interval of 109 months (IQR, 54-126 months).

CONCLUSION

SDH-deficient GISTs occur in young patients, commonly arise in stomach, can be multifocal and may be associated with Carney triad or Carney-Stratakis syndrome. They frequently metastasize to lymph nodes in addition to the liver and peritoneum and are associated with indolent course despite metastatic spread.

ADVANCES IN KNOWLEDGE

The presence of features unusual for conventional GIST on imaging should alert the radiologist for the possibility of SDH-deficient GIST, especially, because SDH-deficient GISTs are resistant to imatinib. Young age at diagnosis, prolonged survival, association with Carney triad and Carney-Stratakis syndrome and occurrence of concurrent renal cell carcinoma and thyroid malignancies necessitates long-term follow-up of patients with SDH-deficient GISTs.

A multicenter phase II study of pazopanib in patients with advanced gastrointestinal stromal tumors (GIST) following failure of at least imatinib and sunitinib

BACKGROUND

Advanced GISTs are incurable, but often treatable for years with tyrosine kinase inhibitors (TKIs). The majority of GISTs harbor an oncogenic activating mutation in KIT or PDGFRA. Inhibition of this activating mutation with TKIs most often leads to durable disease control for many patients. However, almost all patients develop resistance to these TKIs, typically due to the development of secondary mutations, heralding the need for new therapeutic options. We conducted a phase II study evaluating the efficacy and toxicity of pazopanib, a broad spectrum TKI inhibiting KIT, VEGFRs (-1, -2, and -3), and PDGFR (-α and-β) in patients with advanced GIST following failure of at least imatinib and sunitinib.

METHODS

Patients received pazopanib 800 mg orally once daily. All patients were assessed for efficacy with CT scans every 8 weeks (two cycles). Patients continued pazopanib until progression or unacceptable toxicity. The primary end point was the 24-week nonprogression [complete response+partial response+stable disease (SD)] rate (NPR) per RECIST 1.1. Secondary end points included PFS, OS, and toxicity.

RESULTS

Between August 2011 and September 2012, a total of 25 patients were treated at two institutions. Median number of prior therapy was 3 (range 2-7). A total of 90 cycles of pazopanib were administered, with a median of two cycles (range 1 to 17+) per patient. Best response of SD at any time was observed in 12 (48%) patients. The NPR was 17% [95% confidence interval (CI) 4.5-37]. All but one patient discontinued protocol either due to PD (n = 19) or intolerance (n = 4). One patient with succinate dehydrogenase (SDH)-deficient GIST exhibited continuing disease control after 17 cycles. The median PFS for the entire cohort was 1.9 months (95% CI 1.6-5.2), and the median OS was 10.7 months (95% CI 3.9-NR).

CONCLUSIONS

Pazopanib was reasonably well tolerated with no unexpected toxicities. Pazopanib as a single agent has marginal activity in unselected heavily pretreated patients with advanced GIST.

Fluctuating ideal-gas lattice Boltzmann method with fluctuation dissipation theorem for nonvanishing velocities

Current implementations of fluctuating ideal-gas descriptions with the lattice Boltzmann methods are based on a fluctuation dissipation theorem, which, while greatly simplifying the implementation, strictly holds only for zero mean velocity and small fluctuations. We show how to derive the fluctuation dissipation theorem for all k, which was done only for k=0 in previous derivations. The consistent derivation requires, in principle, locally velocity-dependent multirelaxation time transforms. Such an implementation is computationally prohibitively expensive but, with a small computational trick, it is feasible to reproduce the correct FDT without overhead in computation time. It is then shown that the previous standard implementations perform poorly for non vanishing mean velocity as indicated by violations of Galilean invariance of measured structure factors. Results obtained with the method introduced here show a significant reduction of the Galilean invariance violations.

Survey of morphologies formed in the wake of an enslaved phase-separation front in two dimensions

A phase-separation front will leave in its wake a phase-separated morphology that differs markedly from homogeneous phase-separation morphologies. For a purely diffusive system such a front, moving with constant velocity, will generate very regular, nonequilibrium structures. We present here a numerical study of these fronts using a lattice Boltzmann method. In two dimensions these structures are regular stripes or droplet arrays. In general the kind and orientation of the selected morphology and the size of the domains depends on the speed of the front as well as the composition of the material overtaken by the phase-separation front. We present a survey of morphologies as a function of these two parameters. We show that the resulting morphologies are initial condition dependent. We then examine which of the potential morphologies is the most stable. An analytical analysis for symmetrical compositions predicts the transition point from orthogonal to parallel stripes.

17-DMAG targets the nuclear factor-kappaB family of proteins to induce apoptosis in chronic lymphocytic leukemia: clinical implications of HSP90 inhibition

The HSP90 client chaperone interaction stabilizes several important enzymes and antiapoptotic proteins, and pharmacologic inhibition of HSP90 results in rapid client protein degradation. Therefore, HSP90 inhibition is an attractive therapeutic approach when this protein is active, a phenotype commonly observed in transformed but not normal cells. However, preclinical studies with HSP90 inhibitors such as 17-AAG demonstrated depletion of only a subset of client proteins and very modest tumor cytotoxicity in chronic lymphocytic leukemia (CLL) cells. Herein, we describe another HSP90 inhibitor, 17-DMAG, which is cytotoxic to CLL but not normal lymphocytes. Treatment with 17-DMAG leads to depletion of the HSP90 client protein IKK, resulting in diminished NF-kappaB p50/p65 DNA binding, decreased NF-kappaB target gene transcription, and caspase-dependent apoptosis. Furthermore, treatment with 17-DMAG significantly decreased the white blood cell count and prolonged the survival in a TCL1-SCID transplant mouse model. The ability of 17-DMAG to function as an NF-kappaB inhibitor is of great interest clinically, as few currently available CLL drugs target this transcription factor. Therefore, the effect of 17-DMAG on NF-kappaB signaling pathways represents a novel therapy warranting further clinical pursuit in this and other B-cell lymphoproliferative disorders.

Experimental study of a planar atmospheric-pressure plasma operating in the microplasma regime

Electrical characterization of a nonthermal radio-frequency atmospheric-pressure microplasma in a parallel plate configuration has shown that reducing electrode gap into the submillimeter range increases current and power density at a reduced voltage as compared to similar plasmas at larger electrode gaps which have no gap dependence. Calculation of sheath thickness and electric fields in the sheath and in the bulk demonstrate a dependence on the electrode gap as it is reduced into the submillimeter regime, indicating a distinct regime of operation.

Phase II study of flavopiridol in relapsed chronic lymphocytic leukemia demonstrating high response rates in genetically high-risk disease

PURPOSE

Patients with chronic lymphocytic leukemia (CLL) with high-risk genomic features achieve poor outcomes with traditional therapies. A phase I study of a pharmacokinetically derived schedule of flavopiridol suggested promising activity in CLL, irrespective of high-risk features. Given the relevance of these findings to treating genetically high-risk CLL, a prospective confirmatory study was initiated.

PATIENTS AND METHODS

Patients with relapsed CLL were treated with single-agent flavopiridol, with subsequent addition of dexamethasone to suppress cytokine release syndrome (CRS). High-risk genomic features were prospectively assessed for response to therapy.

RESULTS

Sixty-four patients were enrolled. Median age was 60 years, median number of prior therapies was four, and all patients had received prior purine analog therapy. If patients tolerated treatment during week 1, dose escalation occurred during week 2. Dose escalation did not occur in four patients, as a result of severe tumor lysis syndrome; three of these patients required hemodialysis. Thirty-four patients (53%) achieved response, including 30 partial responses (PRs; 47%), three nodular PRs (5%), and one complete response (1.6%). A majority of high-risk patients responded; 12 (57%) of 21 patients with del(17p13.1) and 14 (50%) of 28 patients with del(11q22.3) responded irrespective of lymph node size. Median progression-free survival among responders was 10 to 12 months across all cytogenetic risk groups. Reducing the number of weekly treatments per cycle from four to three and adding prophylactic dexamethasone, which abrogated interleukin-6 release and CRS (P < or = .01), resulted in improved tolerability and treatment delivery.

CONCLUSION

Flavopiridol achieves significant clinical activity in patients with relapsed CLL, including those with high-risk genomic features and bulky lymphadenopathy. Subsequent clinical trials should use the amended treatment schedule developed herein and prophylactic corticosteroids.

Enslaved phase-separation fronts in one-dimensional binary mixtures

Phase-separation fronts leave in their wakes morphologies that are substantially different from the morphologies formed in homogeneous phase separation. In this paper we focus on fronts in binary mixtures that are enslaved phase-separation fronts, i.e., fronts that follow in the wake of a control-parameter front. In the one-dimensional case, which is the focus of this paper, the formed morphology is deceptively simple: alternating domains of a regular size. However, determining the size of these domains as a function of the front speed and other system parameters is a nontrivial problem. We present an analytical solution for the case where no material is deposited ahead of the front and numerical solutions and scaling arguments for more general cases. Through these enslaved phase-separation fronts large domains can be formed that are practically unattainable in homogeneous one-dimensional phase separation.

Genetic analysis of congenital cystic adenomatoid malformation reveals a novel pulmonary gene: fatty acid binding protein-7 (brain type)

The pathogenesis of congenital cystic adenomatoid malformation (CCAM) is unknown and its natural history is unpredictable. Fatty acid binding protein-7 (FABP-7) has been previously described in brain and breast development, but never before in the lung. We investigate gene expression in CCAM, and hypothesize that CCAM results from an aberration in the signaling pathway during lung development. Under IRB approval, tissue specimens of fetal CCAM, fetal control, postnatal CCAM, and postnatal control were examined and microarray analysis was performed. Candidate differentially expressed genes were selected with log-odds ratio (B) >0 and false discovery rate <0.05. Validation of differential expression was achieved at the RNA and protein levels. FABP-7 was underexpressed in fetal CCAM compared with fetal lung in both the microarray and by RT-PCR. Findings were duplicated by Western Blot analysis and immunohistochemistry. This is the first description of FABP-7 in the human lung. Decreased expression of FABP-7 in fetal CCAM compared with normal fetal lung at both the RNA and protein levels suggests FABP-7 may have a role in pulmonary development and in the pathogenesis of CCAM.

Interface width and bulk stability: requirements for the simulation of deeply quenched liquid-gas systems

Simulations of liquid-gas systems with interface terms evaluated by central difference discretizations are observed to fail to give accurate results for two reasons: the interface can get "stuck" on the lattice or a density overshoot develops around the interface. In the first case, the bulk densities can take a range of values, dependent on the initial conditions. In the second case, inaccurate bulk densities are found. We derived the minimum interface width required for the accurate simulation of liquid-gas systems with a diffuse interface. This criterion is demonstrated for lattice Boltzmann simulations of a van der Waals gas. Combining this criterion with predictions for the bulk stability defines the parameter range for stable and accurate simulation results even for high density ratios of over 1000.

Symmetric free-energy-based multicomponent lattice Boltzmann method

We present a lattice Boltzmann algorithm based on an underlying free energy that allows the simulation of the dynamics of a multicomponent system with an arbitrary number of components. The thermodynamic properties, such as the chemical potential of each component and the pressure of the overall system, are incorporated in the model. We derived a symmetrical convection diffusion equation for each component as well as the Navier Stokes equation and continuity equation for the overall system. The algorithm was verified through simulations of binary and ternary systems. The equilibrium concentrations of components of binary and ternary systems simulated with our algorithm agree well with theoretical expectations.