The association between antenatal corticosteroids exposure and postnatal growth in infants born between 23 and 29 weeks of gestation

OBJECTIVE

To assess the association between antenatal corticosteroids exposure and postnatal growth in infants born at 23-29 weeks' gestation.

STUDY DESIGN

This retrospective study used data from the Pediatrix Clinical Data Warehouse. Maternal-infant dyads from 2018 to 2020 were included. Inverse propensity weighting (IPW) was applied to balance pre-treatment confounders. Primary outcomes included postnatal weight, length, and head circumference growth trajectory percentiles.

RESULT

The unadjusted cohort consisted of 11,912 dyads. After IPW adjustment, there were 23,231 dyads. Exposed infants showed higher postnatal trajectory percentiles for weight (by 3.4%), length (by 1.8%), and head circumference (by 2.5%) when compared to non-exposed infants. The positive association between antenatal corticosteroids and postnatal growth was only observed in infants not exposed to preeclampsia/eclampsia/HELLP syndrome or without fetal growth restriction.

CONCLUSION

Antenatal corticosteroids exposure is associated with better postnatal growth. The study is limited by its retrospective nature.

Perceptions and impact of patient reviews: a survey of academic dermatologists

BACKGROUND

Patient reviews (PRs) have emerged as a method to assess patient experiences with healthcare in order to improve the quality of care. Both institutional and third-party organizations collect quantitative data and comments from these patient surveys, usually accessible to the public for review. Our study examined dermatologists' perceptions of PRs and assessed their impact on dermatologists.

METHODS

A survey was sent to the Association of Professors of Dermatology listserv (response rate 30%).

RESULTS

Most respondents disagreed with the statements that PRs are good for doctors (63%), good for patients (58%), helpful for doctors (58%), or that high PRs indicate being a good doctor (65%). The majority disagreed that PRs should be available publicly (60%). Respondents agreed that PRs contribute to depersonalization (60%), energy depletion or exhaustion (55%), added stress at work (70%), negativism/cynicism about work (60%), and diminished professional efficacy (29%). Self-identified female respondents were more likely to agree that PRs added stress to work compared to self-identified males (66% vs. 42%, P < 0.05).

CONCLUSIONS

Overall, these findings suggest that PRs may negatively impact dermatologists' well-being and perceived stress levels.

The association between bronchopulmonary dysplasia grade and risks of adverse neurodevelopmental outcomes among preterm infants born at less than 30 weeks of gestation

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a multifactorial disease with neurodevelopmental implications. This study aims to quantify the risks of adverse neurodevelopmental outcomes for each BPD grade among preterm infants born at less than 30 weeks' gestation.

METHODS

We retrospectively studied infants who received care in our institution until at least 36 weeks postmenstrual age and had a formal neurodevelopmental assessment in our infant follow-up clinic using the Bayley Scales for Infant and Toddler Development (BSID). We assessed the association between BPD grade and adverse neurodevelopmental outcomes using descriptive statistics and regression models.

RESULTS

Two hundred and fifty infants, including 89 (35.6%), 87 (34.8%), 65 (20.6%), and 9 (3.6%) with No BPD, Grade 1, Grade 2, and Grade 3 BPD, were included in the study. Small for gestational age, late pulmonary hypertension, dexamethasone administration, and adverse neurodevelopmental outcomes were more common as BPD grade increased. In a logistic regression analysis, Grades 2 and 3, but not Grade 1, BPD were associated with increased odds of a composite adverse neurodevelopmental outcome by 2.7 and 7.2 folds, respectively. A BSID domain-specific analysis showed that higher grades were associated with lower scores in the cognitive, gross motor, and fine motor domains.

CONCLUSIONS

Grades 2 and 3 BPD, but not Grade 1, correlate with risks of adverse neurodevelopmental outcomes at a grade-dependent manner in our single-center cohort retrospective study. Further validation using a multi-center large cohort is warranted.

Comparison of Adverse Clinical Outcomes in Children Hospitalized for Myocarditis with and Without COVID-19

We used a nationally representative database of the US, which included 1995 myocarditis cases, among whom 620 children had COVID-19. While the risk of in-hospital mortality was not higher, illness severity and length of hospital stay were higher in patients with myocarditis and COVID-19 than those without COVID-19.

When the Unknown Is Unknowable: Confronting Diagnostic Uncertainty

The neonatology literature often refers to medical uncertainty and specifically the challenges of predicting morbidity for extremely premature infants, who can have widely varying outcomes. Less has been written about situations in which diagnoses are simply unknown or unattainable. This case highlights the importance of communication amidst uncertainty from a lack of knowledge about aspects of a patient's condition. Using epidemiologic and clinical reasoning, the authors challenge the assumption that diagnostic uncertainty must necessarily portend prognostic uncertainty. When physicians' quest for a diagnosis becomes burdensome and detrimental to the infant's quality of life, this should be abandoned and replaced by focusing on prognosis. The authors focus on the shift of the physician's role toward one of support, assisting the family in ascribing meaning to the dying experience. By focusing on prognosis and support, communication can proceed with more clarity, understanding, and empathy.

A comparative study of postnatal anthropometric growth in very preterm infants and intrauterine growth

Most growth references for very preterm infants were developed using measurements taken at birth, and were thought to represent intrauterine growth. However, it remains unclear whether the goal of approximating an intrauterine growth rate as stated by the American Academy of Pediatrics is attainable by very preterm infants. Using real-world measurement data from very preterm infants born between 2010 through 2020, we develop models to characterize the patterns of postnatal growth, and compare them to intrauterine growth. By assessing the weight growth rate, we show three phases of postnatal growth not evident in intrauterine growth. Furthermore, postnatal length and head circumference growth exhibit a slow rate after birth, followed by an acceleration. Collectively, postnatal and intrauterine growth are distinctly different. Although postnatal growth models do not represent optimal growth of very preterm infants, they can serve as a practical tool for clinical assessment of growth and for nutrition research.

Impact of congenital heart disease on outcomes among pediatric patients hospitalized for COVID-19 infection

BACKGROUND

COVID-19 infection is generally regarded as an acute self-limiting illness in children, but it can cause significant morbidity and mortality in both healthy and high-risk children. There are limited data on the outcomes of children with congenital heart disease (CHD) and COVID-19. This study aimed to examine the risks of mortality, in-hospital cardiovascular and non-cardiovascular complications in this patient population.

METHODS

We analyzed data from hospitalized pediatric patients from 2020 using the nationally representative National Inpatient Sample (NIS). Children hospitalized for COVID-19 were included, and weighted data were used to compare in-hospital mortality and morbidities between children with and without CHD.

RESULTS

Out of 36,690 children admitted with a diagnosis of COVID-19 infection(ICD-10 code:U07.1 and B97.29) during calendar year 2020, 1240 (3.4%) had CHD. The risk of mortality in children with CHD was not significantly higher than those without CHD(1.2% vs. 0.8%, p = 0.50), with adjusted OR (aOR) of 1.7 (95% CI: 0.6-5.3). Tachyarrhythmias and heart block were more likely in CHD children with an aOR of 4.2 (95% CI: 1.8-9.9) and aOR of 5.0 (95% CI: 2.4-10.8), respectively. Similarly, respiratory failure [aOR = 2.0 (1.5-2.8)], respiratory failure requiring non-invasive mechanical ventilation [aOR = 2.7 (1.4-5.2)] and invasive mechanical ventilation [aOR = 2.6 (1.6-4.0)], and acute kidney injury [aOR = 3.4 (2.2-5.4)] were all significantly higher among patients with CHD. Median length of hospital stay in children with CHD was longer than those without CHD [5 days (IQR: 2-11) vs. 3 days (IQR: 2-5), p = < 0.001].

CONCLUSIONS

Children with CHD hospitalized with COVID-19 infection were at increased risk of serious cardiovascular and non-cardiovascular adverse clinical outcomes. They also had increased length of hospital stay and utilization of healthcare resources.

Oxygenation index in the first three weeks of life is a predictor of bronchopulmonary dysplasia grade in very preterm infants

BACKGROUND

The new bronchopulmonary dysplasia (BPD) grading system was developed based on its correlation with long-term respiratory and neurodevelopmental outcomes and may provide better personalized prognostication. Identifying early-life predictors for accurate BPD grade prediction may allow interventions to be tailored to individual needs. This study aimed to assess whether oxygenation index (OI) dynamics in the first three weeks of life are a predictor of BPD grade.

METHODS

A single-center retrospective study was performed. Generalized additive mixed modeling was used to model OI trajectories for each BPD grade subgroup. A multinomial regression model was then developed to quantify the association between OI dynamics and BPD grade.

RESULTS

Two hundred fifty-four infants were identified for inclusion in the trajectory modeling. A total of 6,243 OI data points were available for modeling. OI trajectory estimates showed distinct patterns in the three groups, most prominent during the third week of life. The average daily OI change was -0.33 ± 0.52 (n = 85) in the No-BPD group, -0.04 ± 0.75 (n = 82) in the Low-Grade BPD group, and 0.22 ± 0.65 (n = 75) in the High-Grade BPD group (p < 0.001). A multinomial regression analysis showed the initial OI value and the average daily OI change both independently correlated with BPD grade outcomes after adjusting for birth gestation, birth weight z-score, sex, and the duration of invasive ventilation.

CONCLUSION

Early-life OI dynamics may be a useful independent marker for BPD grade prediction. Prospective studies may be warranted to further validate the findings.

Machine learning for prediction of bronchopulmonary dysplasia-free survival among very preterm infants

Background

Bronchopulmonary dysplasia (BPD) is one of the most common and serious sequelae of prematurity. Prompt diagnosis using prediction tools is crucial for early intervention and prevention of further adverse effects. This study aims to develop a BPD-free survival prediction tool based on the concept of the developmental origin of BPD with machine learning.

Methods

Datasets comprising perinatal factors and early postnatal respiratory support were used for initial model development, followed by combining the two models into a final ensemble model using logistic regression. Simulation of clinical scenarios was performed.

Results

Data from 689 infants were included in the study. We randomly selected data from 80% of infants for model development and used the remaining 20% for validation. The performance of the final model was assessed by receiver operating characteristics which showed 0.921 (95% CI: 0.899–0.943) and 0.899 (95% CI: 0.848–0.949) for the training and the validation datasets, respectively. Simulation data suggests that extubating to CPAP is superior to NIPPV in BPD-free survival. Additionally, successful extubation may be defined as no reintubation for 9 days following initial extubation.

Conclusions

Machine learning-based BPD prediction based on perinatal features and respiratory data may have clinical applicability to promote early targeted intervention in high-risk infants.

Impaired Cell Cycle Progression and Self-Renewal of Fetal Neural Stem and Progenitor Cells in a Murine Model of Intrauterine Growth Restriction

Individuals with intrauterine growth restriction (IUGR) are at an increased risk for neurodevelopmental impairment. Fetal cortical neurogenesis is a time-sensitive process in which fetal neural stem cells (NSCs) follow a distinct pattern of layer-specific neuron generation to populate the cerebral cortex. Here, we used a murine maternal hypoxia-induced IUGR model to study the impact of IUGR on fetal NSC development. In this model, timed-pregnant mice were exposed to hypoxia during the active stage of neurogenesis, followed by fetal brain collection and analysis. In the IUGR fetal brains, we found a significant reduction in cerebral cortical thickness accompanied by decreases in layer-specific neurons. Using EdU labeling, we demonstrated that cell cycle progression of fetal NSCs was delayed, primarily observed in the G2/M phase during inward interkinetic nuclear migration. Following relief from maternal hypoxia exposure, the remaining fetal NSCs re-established their neurogenic ability and resumed production of layer-specific neurons. Surprisingly, the newly generated neurons matched their control counterparts in layer-specific marker expression, suggesting preservation of the fetal NSC temporal identity despite IUGR effects. As expected, the absolute number of neurons generated in the IUGR group remained lower compared to that in the control group due to a reduced fetal NSC pool size as a result of cell cycle defect. Transcriptome analysis identified genes related to energy expenditure and G2/M cell cycle progression being affected by maternal hypoxia-induced IUGR. Taken together, maternal hypoxia-induced IUGR is associated with a defect in cell cycle progression of fetal NSCs, and has a long-term impact on offspring cognitive development.

Quantifying Fetal Reprogramming for Biomarker Development in the Era of High-Throughput Sequencing

Gestational hypertensive disorders continue to threaten the well-being of pregnant women and their offspring. The only current definitive treatment for gestational hypertensive disorders is delivery of the fetus. The optimal timing of delivery remains controversial. Currently, the available clinical tools do not allow for assessment of fetal stress in its early stages. Placental insufficiency and fetal growth restriction secondary to gestational hypertensive disorders have been shown to have long-term impacts on offspring health even into their adulthood, becoming one of the major focuses of research in the field of developmental origins of health and disease. Fetal reprogramming was introduced to describe the long-lasting effects of the toxic intrauterine environment on the growing fetus. With the advent of high-throughput sequencing, there have been major advances in research attempting to quantify fetal reprogramming. Moreover, genes that are found to be differentially expressed as a result of fetal reprogramming show promise in the development of transcriptional biomarkers for clinical use in detecting fetal response to placental insufficiency. In this review, we will review key pathophysiology in the development of placental insufficiency, existing literature on high-throughput sequencing in the study of fetal reprogramming, and considerations regarding research design from our own experience.

Machine Learning for Mortality Prediction in Pediatric Myocarditis

Background: Pediatric myocarditis is a rare disease. The etiologies are multiple. Mortality associated with the disease is 5-8%. Prognostic factors were identified with the use of national hospitalization databases. Applying these identified risk factors for mortality prediction has not been reported. Methods: We used the Kids' Inpatient Database for this project. We manually curated fourteen variables as predictors of mortality based on the current knowledge of the disease, and compared performance of mortality prediction between linear regression models and a machine learning (ML) model. For ML, the random forest algorithm was chosen because of the categorical nature of the variables. Based on variable importance scores, a reduced model was also developed for comparison. Results: We identified 4,144 patients from the database for randomization into the primary (for model development) and testing (for external validation) datasets. We found that the conventional logistic regression model had low sensitivity (~50%) despite high specificity (>95%) or overall accuracy. On the other hand, the ML model struck a good balance between sensitivity (89.9%) and specificity (85.8%). The reduced ML model with top five variables (mechanical ventilation, cardiac arrest, ECMO, acute kidney injury, ventricular fibrillation) were sufficient to approximate the prediction performance of the full model. Conclusions: The ML algorithm performs superiorly when compared to the linear regression model for mortality prediction in pediatric myocarditis in this retrospective dataset. Prospective studies are warranted to further validate the applicability of our model in clinical settings.

Impact of congenital heart disease on outcomes among pediatric patients hospitalized for influenza infection

Background

Young children and those with chronic medical conditions are at risk for complications of influenza including cardiopulmonary compromise. Here we aim to examine risks of mortality, clinical complications in children with congenital heart disease (CHD) hospitalized for influenza.

Methods

We analyzed data from in-hospital pediatric patients from 2003, 2006, 2009, 2012 and 2016 using the nationally representative Kids Inpatient Database (KID). We included children 1 year and older and used weighted data to compare the incidence of in-hospital mortality and rates of complications such as respiratory failure, acute kidney injury, need for mechanical ventilation, arrhythmias and myocarditis.

Results

Data from the KID estimated 125,470 children who were admitted with a diagnosis of influenza infection. Out of those, 2174(1.73%) patients had discharge diagnosis of CHD. Children with CHD who required hospitalization for influenza had higher in-hospital mortality (2.0% vs 0.5%), with an adjusted OR (aOR) of 2.8 (95% CI: 1.7–4.5). Additionally, acute respiratory failure and acute kidney failure were more likely among patients with CHD, with aOR of 1.8 (95% CI: 1.5–2.2) and aOR of 2.2 (95% CI: 1.5–3.1), respectively. Similarly, the rate of mechanical ventilatory support was higher in patients with CHD compared to those without, 14.1% vs 5.6%, aOR of 1.9 (95% CI: 1.6–2.3). Median length of hospital stay in children with CHD was longer than those without CHD [4 (IQR: 2–8) days vs. 2 (IQR: 2–4) days]. Outcomes were similar between those with severe vs non-severe CHD.

Conclusions

Children with CHD who require hospital admission for influenza are at significantly increased risk for in-hospital mortality, morbidities, emphasizing the need to reinforce preventative measures (e.g. vaccination, personal hygiene) in this particularly vulnerable population.

Assessment of social factors influencing hospitalization cost of US preterm newborns, 2016

Background and objective: Preterm newborn (PTN) care is costly in the US, and the preterm birth (PTB) rate has not seen substantial improvement. PTB remains a significant public health issue because of risks of adverse health outcomes and the associated economic burden. Assessing factors leading to high hospital cost is imperative in order to ease economic burden associated with PTB. Social factors influencing hospitalization cost for PTN have not been studied extensively. This study aims to examine the contributions of hospital type, race/ethnicity, and median household income quartile to the cost of the PTN's initial hospitalization after birth.Materials and methods: Data used in this study originated from the 2016 Healthcare Cost and Utilization Project Kids' Inpatient Database (KID) which provided the most recent national records of pediatric hospitalization in the US. International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes P07.2x and P07.3x were used to identify birth gestational age (GA) in complete weeks. Q00-Q99 codes were used to identify congenital anomalies. Data records reflecting hospitalization of newborns without congenital anomalies were extracted to estimate total cost in 2016. Analysis of factors influencing total cost was performed on the subset of newborns that were in-born and with birth GA from 24 to 36 weeks. Total hospital cost was calculated by multiplying total charges and cost-to-charge ratios. Per-diem cost was calculated by dividing total hospital cost by length of stay. Linear regression modeling was performed using weighted data, and the best model was selected using the Akaike information criteria. Results: Hospitalization cost for PTNs, who constituted 7.6% of all studied newborns, comprised 45% of total newborn hospitalization cost. PTNs in freestanding children's hospitals had significantly higher total cost compared to non-children's teaching and non-teaching hospitals. The cost difference was GA-dependent. The latter two hospital types reported similar cost for PTNs. Although race/ethnicity and median household income quartile were related, the two covariates had independent effects on total hospitalization cost. A model built to assess the roles of covariates in the association between GA and total hospitalization cost found that all three covariates independently affected total cost when controlling for one another, with hospital type also showing an interaction effect with GA.Conclusions: Hospitalization cost is highly influenced by hospital type, race/ethnicity, and median household income quartile. The modifiable aspects of these factors may be further dissected and targeted in order to ease the burden of high hospitalization cost associated with PTB.

The SLC25A42 Transcript Is a Biomarker for Fetal Reprogramming in Response to Placental Insufficiency in Preterm Newborns Under 32 Weeks Gestation-A Pilot Study

Introduction: Timing of medical delivery of preterm newborns exposed to placental insufficiency is largely determined by umbilical artery blood flow and maternal clinical manifestations. There is a lack of tools to properly assess fetal body response to placental insufficiency before or upon delivery. Yet, short- and long-term comorbidities associated with placental insufficiency and the consequential intrauterine growth restriction may be a result of fetal response following prolonged stress. This study aims to establish a procedure to investigate fetal/neonatal transcriptional response to placental insufficiency as part of an initiative to identify cost-effective biomarkers for assessing fetal response to placental insufficiency. Methods: A prospective pilot study involving newborns with birth gestation <32 weeks was conducted to compare gene expression profiles in whole blood collected at birth among three clinically distinct groups - preeclampsia without placental insufficiency (PE), placental insufficiency (PI), and non-PE/PI groups. Results: Whole blood from 11, 3, and 6 newborns in the non-PE/PI, PE, and PI groups were obtained. A transcriptome analysis found that the majority of the genes were downregulated in the PI group, suggesting global transcriptional inactivation. Intriguingly, SLC25A42, which encodes a mitochondrial transporter for coenzyme A and adenosine-3',5'-diphosphate, was significantly upregulated in the PI group. Conclusion: Transcriptional biomarkers for assessing fetal response to placental insufficiency may provide a useful tool to better understand the pathophysiology of fetal reprogramming in response to placental insufficiency. The validity and the role of SLC25A42, as well as its correlation with short- and long-term neonatal outcomes, warrants further investigation.

Comparison of In-Hospital Outcomes When Repair of Tetralogy of Fallot Is in the Neonatal Period Versus in the Post-Neonatal Period

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease (CHD) and optimal timing for total repair of TOF is controversial. We hypothesize that TOF repair in the neonatal period is associated with worse outcomes compared with those who undergo repair later in infancy. We analyzed data using the Kids' Inpatient Database (KID) from 2003 to 2012. We used multivariable logistic regression analyses to compare the in-hospital outcomes between those who underwent total repair of TOF during the neonatal period vs the postneonatal period. There were 6,856 cases of TOF and 7.83% (n = 537) of those underwent repair during the neonatal period. The average mortality in all TOF repair was 2.1% (n = 147). In multiple regression model, compared with repair in postneonatal period, neonatal repair was associated with increased mortality, with adjusted odds ratio of 2.2 (95% confidence interval [CI]: 1.1 to 4.3, p = 0.023). Regarding complications, the neonatal group was associated with higher risk of acute renal failure (8.9% vs 2.3%, p <0.001), need for cardiac catheterization (18.6% vs 8.3%, p <0.001), and ECMO use (4.4% vs1.6%, p <0.001). There was no difference in the rates of arrhythmia, respiratory failure, pulmonary hypertension, or sudden cardiac arrest. Children who underwent repair in the neonatal period had longer hospital stay compared with the postneonatal group (45.5 days [95% CI: 39.3 to 51.7] vs 12.6 days [95% CI: 11.7 to 13.4], p <0.001). Hospital charges were higher for children who underwent repair in the neonatal period compared with those in the postneonatal period. In conclusion, TOF repair in the neonatal period is associated with higher rates of mortality, more postoperative complications, longer hospital stays, and higher hospitalization cost.

Socioeconomic and racial disparities in the prevalence of congenital heart disease in infants of diabetic mothers

Infants of diabetic mothers (IDM) are at increased risk for congenital heart disease (CHD). There is little information in the literature about the impact of economic status and race/ethnicity on the prevalence of CHD in IDM. Using the KID national database collected from 2003 to 2012, we studied over 180,000 IDM to compare the prevalence of CHD according to family income and race/ethnicity. There were 9214 (5.02%) CHDs out of 183 453 IDM. We found significant impact of family income and race/ethnicity on the prevalence of CHD. Specifically, compared to IDM born in a family with highest 25th quartile family income, infants in the lowest 25th quartile family income had higher odds of CHD with unadjusted odds ratio (OR) of 1.6 [(95% confidence interval (CI): 1.4-1.7), p < .001]. In terms of racial/ethnic differences, Black [unadjusted OR = 1.4 (95% CI: 1.3-1.5), p < .001] and Hispanic [unadjusted OR 1.26 (95% CI: 1.2-1.4), p < .001] IDM are more likely, and Asians [0.69 (95% CI: 0.59-0.81), p < .001] were less likely to have CHD when compared to whites. When adjusting race/ethnicity for family income quartile and vice versa, we did not observe changes in the estimates, suggesting that family income and race/ethnicity impact on the odds of CHD independently. Our report of higher prevalence of CHD among IDM in ethnic minorities and lower socioeconomic status would warrant more studies to further dissect causes of higher prevalence in these subpopulations.

Live-cell Migration Assays to Study Motility of Neural andGlial (Oligodendrocyte) Progenitor Cells

Cell motility has been extensively studied in in vitro models using fibroblasts and keratocytes, but the cell type-specific mechanisms underlying migration of lineage- or disease-specific cells, such as neural and glial progenitor cells, remain an active field for investigation. The migrating neural and glial progenitor cells contribute to the development, tissue repair and tumor invasion in the central nervous system (CNS). Cell migration is a highly dynamic process which relies on membranous protrusions to assemble, extend, disassemble and retract. In the CNS, the motility of neural and glial progenitor cells is affected by various cell-autonomous and non-cell-autonomous mechanisms such as signaling molecules, actin and microtubule interactions, and environmental cues. Here, we described a live-cell migration assay for use in the assessment of neural and glial progenitor cell migration. We first will demonstrate the procedures for isolating and culturing neural and glial progenitor cells. Next, we will demonstrate the acquisition of time-lapse images using phase contrast microscopy, the methods for quantification and the analyses of various motility parameters including speed, velocity, straightness and leading-edge dynamics. This method allows researchers to dissect the mechanisms of cell motility in response to different environmental cues, such as chemoattractive and repulsive signals, matrix adhesiveness and stiffness. This assay also allows researchers to study migration of pharmacologically and genetically manipulated cells.

Use of mean platelet volume in the assessment of intrauterine infection in newborns with combined thrombocytopenia and leukopenia at birth

Objective: Intrauterine stress can be reflected on hematological disturbance at birth. Thrombocytopenia and leukopenia may be a result of exposure to maternal hypertensive disorders but may also indicate fetal inflammatory response to intrauterine infection, prompting empiric antibiotics use during the initial assessment after birth. Emerging data suggest long-term adverse health outcomes associated with antibiotics exposure early in life. In this report, we sought to assess the use of mean platelet volume (MPV) at birth in predicting fetal inflammatory response in newborns with combined thrombocytopenia and leukopenia.Materials and methods: This is a retrospective study from a single academic medical center. Data were collected prospectively on all newborns with thrombocytopenia and leukopenia within the first 24 h of life. The primary outcome was a composite of fetal tachycardia, premature preterm rupture of membrane with preterm labor, and histological evidence of chorioamnionitis/funisitis/villitis on placental pathology reports evaluated using a multiple logistical regression analysis.Results: The prevalence of combined thrombocytopenia and leukopenia was 5.8% (99 out of 1693 newborns) during the study period. The prevalence was highly associated with gestational age (R² = 0.873). Twenty-four (32.4%) had abnormal MPV values at birth, defined as MPV > 9 or < 7 fL. Newborns with abnormal MPV had lower platelet counts and were more likely to have I:T ratio ≥0.2. In a univariate analysis, abnormal MPV (OR: 6.205, 95% CI: 1.923-20.022, p = .002), I:T ratio ≥0.2 (OR: 8.462, 95% CI: 1.396-51.281, p = .02), and platelet counts (OR: 98.4, 95% CI: 96.9%-99.9%, p = .035) were each significantly associated with a positive composite outcome. In a multivariate analysis, only abnormal MPV remained significantly associated with an increased likelihood of having a positive composite outcome, with an OR of 3.922 (95% CI: 1.094-14.06, p = .036).Conclusions: MPV may be a more reliable marker than I:T ratio ≥0.2 for fetal inflammatory response in newborns with combined thrombocytopenia and leukopenia during the initial assessment of intrauterine infection. Future prospective studies are required to confirm findings from this report.

Improved multilineage human hematopoietic reconstitution and function in NSGS mice

Genetic manipulation of NOD/SCID (NS) mice has yielded numerous sub-strains with specific traits useful for the study of human hematopoietic xenografts, each with unique characteristics. Here, we have compared the engraftment and output of umbilical cord blood (UCB) CD34+ cells in four immune-deficient strains: NS, NS with additional IL2RG knockout (NSG), NS with transgenic expression of human myeloid promoting cytokines SCF, GM-CSF, and IL-3 (NSS), and NS with both IL2RG knockout and transgenic cytokine expression (NSGS). Overall engraftment of human hematopoietic cells was highest in the IL2RG knockout strains (NSG and NSGS), while myeloid cell output was notably enhanced in the two strains with transgenic cytokine expression (NSS and NSGS). In further comparisons of NSG and NSGS mice, several additional differences were noted. NSGS mice were found to have a more rapid reconstitution of T cells, improved B cell differentiation, increased levels of NK cells, reduced platelets, and reduced maintenance of primitive CD34+ cells in the bone marrow. NSGS were superior hosts for secondary engraftment and both strains were equally suitable for experiments of graft versus host disease. Increased levels of human cytokines as well as human IgG and IgM were detected in the serum of humanized NSGS mice. Furthermore, immunization of humanized NSGS mice provided evidence of a functional response to repeated antigen exposure, implying a more complete hematopoietic graft was generated in these mice. These results highlight the important role that myeloid cells and myeloid-supportive cytokines play in the formation of a more functional xenograft immune system in humanized mice.

Efficacy of prophylactic dexmedetomidine in preventing postoperative junctional ectopic tachycardia in pediatric cardiac surgery patients: A systematic review and meta-analysis

BACKGROUND

Junctional ectopic tachycardia is a serious tachyarrhythmic complication following pediatric cardiac surgery. It is difficult to manage and is associated with significant morbidity and mortality. Conventional nonpharmacological and pharmacological measures have shown limited effects. Dexmedetomidine is an α2 agonist which has recently been shown in multiple studies to be effective.

AIMS

The aim of this systematic review with meta-analysis was to evaluate the efficacy of prophylactic dexmedetomidine administration in the prevention of junctional ectopic tachycardia in pediatric patients following cardiac surgeries.

METHODS

We searched MEDLINE, EMBASE, Cochrane, Web of Science, and relevant references published in English before December 20, 2017 and performed meta-analysis on the selected studies, with one group receiving prophylactic perioperative dexmedetomidine administration and another group receiving placebo. The primary outcome was the incidence of junctional ectopic tachycardia, secondary outcomes included bradycardia, hypotension, intensive care unit stay, total hospital stay, inotropic scores, and total mechanical ventilation time. Odds ratio or mean difference with 95% confidence intervals were calculated using a random effect model.

RESULTS

Seven studies (5 prospective randomized studies and 2 retrospective case-controlled studies) with a total of 1616 patients were analyzed. The incidence of junctional ectopic tachycardia in the dexmedetomidine group was significantly reduced compared to placebo. Similarly, intensive care unit stay, inotropic scores, and total mechanical ventilation time were also significantly decreased in the dexmedetomidine group. No significant increases in adverse events were found. Mortality was low in both groups.

CONCLUSION

Prophylactic dexmedetomidine is effective in reducing the incidence of postoperative junctional ectopic tachycardia without significant increases in adverse events in pediatric patients undergoing surgery for congenital heart diseases.

Immortalization of human AE pre-leukemia cells by hTERT allows leukemic transformation

Human CD34+ hematopoietic stem and progenitor cells (HSPC) expressing fusion protein AML1-ETO (AE), generated by the t(8;21)(q22;q22) rearrangement, manifest enhanced self-renewal and dysregulated differentiation without leukemic transformation, representing a pre-leukemia stage. Enabling replicative immortalization via telomerase reactivation is a crucial step in cancer development. However, AE expression alone is not sufficient to maintain high telomerase activity to immortalize human HSPC cells, which may hamper transformation. Here, we investigated the cooperativity of telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase, and AE in disease progression. Enforced expression of hTERT immortalized human AE pre-leukemia cells in a telomere-lengthening independent manner, and improved the pre-leukemia stem cell function by enhancing cell proliferation and survival. AE-hTERT cells retained cytokine dependency and multi-lineage differentiation potential similar to parental AE clones. Over the short-term, AE-hTERT cells did not show features of stepwise transformation, with no leukemogenecity evident upon initial injection into immunodeficient mice. Strikingly, after extended culture, we observed full transformation of one AE-hTERT clone, which recapitulated the disease evolution process in patients and emphasizes the importance of acquiring cooperating mutations in t(8;21) AML leukemogenesis. In summary, achieving unlimited proliferative potential via hTERT activation, and thereby allowing for acquisition of additional mutations, is a critical link for transition from pre-leukemia to overt disease in human cells. AE-hTERT cells represent a tractable model to study cooperating genetic lesions important for t(8;21) AML disease progression.

Molecular components and polarity of radial glial cells during cerebral cortex development

Originating from ectodermal epithelium, radial glial cells (RGCs) retain apico-basolateral polarity and comprise a pseudostratified epithelial layer in the developing cerebral cortex. The apical endfeet of the RGCs faces the fluid-filled ventricles, while the basal processes extend across the entire cortical span towards the pial surface. RGC functions are largely dependent on this polarized structure and the molecular components that define it. In this review, we will dissect existing molecular evidence on RGC polarity establishment and during cerebral cortex development and provide our perspective on the remaining key questions.

The Arp2/3 complex is essential at multiple stages of neural development

During development of the nervous system, radial glial cells perform self-renewing asymmetric divisions and give rise to intermediate progenitor cells (IPC) and neurons. The neuronally committed IPC subsequently undergo multiple rounds of transient amplification and migrate outwards to form cortical layers as they continue to differentiate into mature neurons. Maturing neurons extend protrusions on their cell surface to form neurites, a process called neuritogenesis. Neurite formation results in the establishment of dendrites and axons for synapse formation, which is essential for sensory and motor functions and even higher-level functioning including memory formation and cognitive function, as well as shaping of behavior and emotion. Morphological adaptation during various stages of neural development requires active participation of actin cytoskeleton remodeling. In this review, we aim to discuss current understanding of the Arp2/3 complex branching nucleator in various neural cell types during development and maturation.

Crucial roles of the Arp2/3 complex during mammalian corticogenesis

The polarity and organization of radial glial cells (RGCs), which serve as both stem cells and scaffolds for neuronal migration, are crucial for cortical development. However, the cytoskeletal mechanisms that drive radial glial outgrowth and maintain RGC polarity remain poorly understood. Here, we show that the Arp2/3 complex – the unique actin nucleator that produces branched actin networks – plays essential roles in RGC polarity and morphogenesis. Disruption of the Arp2/3 complex in murine RGCs retards process outgrowth toward the basal surface and impairs apical polarity and adherens junctions. Whereas the former is correlated with an abnormal actin-based leading edge, the latter is consistent with blockage in membrane trafficking. These defects result in altered cell fate, disrupted cortical lamination and abnormal angiogenesis. In addition, we present evidence that the Arp2/3 complex is a cell-autonomous regulator of neuronal migration. Our data suggest that Arp2/3-mediated actin assembly might be particularly important for neuronal cell motility in a soft or poorly adhesive matrix environment.

Summary: During mouse cortical development, the Arp2/3 actin branching complex regulates process formation and the maintenance of radial glial cell polarity, as well as affecting neuronal migration.

Inhibition of Rac GTPase signaling and downstream prosurvival Bcl-2 proteins as combination targeted therapy in MLL-AF9 leukemia

The Rac family of small Rho GTPases coordinates diverse cellular functions in hematopoietic cells including adhesion, migration, cytoskeleton rearrangements, gene transcription, proliferation, and survival. The integrity of Rac signaling has also been found to critically regulate cellular functions in the initiation and maintenance of hematopoietic malignancies. Using an in vivo gene targeting approach, we demonstrate that Rac2, but not Rac1, is critical to the initiation of acute myeloid leukemia in a retroviral expression model of MLL-AF9 leukemogenesis. However, loss of either Rac1 or Rac2 is sufficient to impair survival and growth of the transformed MLL-AF9 leukemia. Rac2 is known to positively regulate expression of Bcl-2 family proteins toward a prosurvival balance. We demonstrate that disruption of downstream survival signaling through antiapoptotic Bcl-2 proteins is implicated in mediating the effects of Rac2 deficiency in MLL-AF9 leukemia. Indeed, overexpression of Bcl-xL is able to rescue the effects of Rac2 deficiency and MLL-AF9 cells are exquisitely sensitive to direct inhibition of Bcl-2 family proteins by the BH3-mimetic, ABT-737. Furthermore, concurrent exposure to NSC23766, a small-molecule inhibitor of Rac activation, increases the apoptotic effect of ABT-737, indicating the Rac/Bcl-2 survival pathway may be targeted synergistically.

Cdc42 regulates extracellular matrix remodeling in three dimensions

Extracellular matrix (ECM) actively participates in normal cell regulation and in the process of tumor progression. The Rho GTPase Cdc42 has been shown to regulate cell-ECM interaction in conventional two-dimensional culture conditions by using dominant mutants of Cdc42 in immortalized cell lines that may introduce nonspecific effects. Here, we employ three-dimensional culture systems for conditional gene targeted primary mouse embryonic fibroblasts that better simulate the reciprocal and adaptive interactions between cells and surrounding matrix to define the role of Cdc42 signaling pathways in ECM organization. Cdc42 deficiency leads to a defect in global cell-matrix interactions reflected by a decrease in collagen gel contraction. The defect is associated with an altered cell-matrix interaction that is evident by morphologic changes and reduced focal adhesion complex formation. The matrix defect is also associated with a reduction in synthesis and activation of matrix metalloproteinase 9 (MMP9) and altered fibronectin deposition patterning. A Cdc42 mutant rescue experiment found that downstream of Cdc42, p21-activated kinase (PAK), but not Par6 or WASP, may be involved in regulating collagen gel contraction and fibronectin organization. Thus, in addition to the previously implicated roles in intracellular regulation of actin organization, proliferation, and vesicle trafficking, Cdc42 is essential in ECM remodeling in three dimensions.

The thrombopoietin/MPL pathway in hematopoiesis and leukemogenesis

Hematopoietic stem cells (HSC) comprise a small percentage of total hematopoietic cells. Their ability to self-renewal is key to the continuous replenishment of the hematopoietic system with newly formed functional blood cell types while maintaining their multipotential capacity. Understanding the extrinsic signals that are essential to HSC maintenance will provide insights into the regulation of hematopoiesis at its most primitive stage, and with the knowledge applied, will potentially lead to improved clinical transplantation outcomes. In this review, we will summarize the current understanding of the role of the thrombopoietin/MPL signaling pathway in HSC maintenance during adult and fetal hematopoiesis. We will also speculate on the downstream key players in the pathway based on published data, and summarize the role of this pathway in leukemia.

Core binding factor at the crossroads: determining the fate of the HSC

Hematopoietic development requires coordinated actions from a variety of transcription factors. The core binding factor (CBF), consisting of a Runx protein and the CBFbeta protein, is a transcription factor complex that is essential for emergence of the hematopoietic stem cell (HSC) from an endothelial cell stage. The hematopoietic defects observed in either Runx1 or CBFbeta knockout mice underscore the necessity of this complex for definitive hematopoiesis. Despite the requirement for CBF in establishing definitive hematopoiesis, Runx1 loss has minimal impact on maintaining the HSC state postnatally, while CBFbeta may continue to be essential. Lineage commitment, on the other hand, is significantly affected upon CBF loss in the adult, indicating a primary role for this complex in modulating differentiation. Given the impact of normal CBF function in the hematopoietic system, the severe consequences of disrupting CBF activity, either through point mutations or generation of fusion genes, are obvious. The physiologic role of CBF in differentiation is subverted to an active process of self-renewal maintenance by the genetic aberrations, through several possible mechanisms, contributing to the development of hematopoietic malignancies including myelodysplastic syndrome and leukemia. The major impact of CBF on the hematopoietic system in both development and disease highlights the need for understanding the intricate functions of this complex and reiterate the necessity of continued efforts to identify potential points of therapeutic intervention for CBF-related diseases.

Troglitazone inhibits cell migration, adhesion, and spreading by modulating cytoskeletal rearrangement in human breast cancer cells

Metastatic tumors are the primary cause of death in patients with breast cancer. Recent data indicate that the peroxisome proliferator-activated receptor gamma (PPARgamma) ligands, thiazolidinediones (TZDs), possess anti-invasive activities on human breast cancer cells. However, the effects of TZDs on other metastatic properties of breast cancer cells such as adhesion, spreading, and migration are not well established. In this study, we show that troglitazone (TG), a member of the TZD family, inhibits lamellipodia formation or membrane ruffling as well as actin polymerization at these structures in MDA-MB-231 and T47D breast cancer cells. In addition, TG reduces migration, adhesion, and spreading on fibronectin (FN)-coated plates. These phenomena were associated with the dramatic decrease of Tyr397 and Tyr576 phosphorylation of focal adhesion kinase (FAK) and the detergent-insoluble Rac1. We also found that TG upregulates Tyr416 phosphorylation of Src, but downregulates the Src-FAK complex. Moreover, we use a PPARgamma-inactive derivative of TG (STG28) and a PPARgamma antagonist (GW9662) to eliminate PPARgamma-mediated effects. We found that treatment with STG28 or GW9662 plus TG showed similar effects compared to TG treatment alone on tyrosine phosphorylation of FAK and Src, indicating that these effects are not the result of PPARgamma activation. Interestingly, we found that TG upregulates actin filament assembly at the point of cell-cell contact in T47D cells, indicating that TG may also upregulate cell-cell adhesion in breast cancer cells which express E-cadherin. These results suggested that TG should be investigated further for its therapeutic potential in metastatic breast cancer.

Thiazolidinediones downregulate Wnt/beta-catenin signaling via multiple mechanisms in breast cancer cells

BACKGROUND

Thiazolidinediones (TZDs) have been demonstrated to possess antitumor effects in breast cancer cells, although the mechanisms are not well established. We sought to better define TZDs' antitumor effects and molecular mechanisms to permit rational utilization of these agents.

MATERIALS AND METHODS

We studied the effects of TZDs on DNA synthesis (BrdU enzyme-linked immunosorbent assay), gene expression (microarray, quantitative reverse transcription-polymerase chain reaction, and immunoblot), serine phosphorylation and localization of beta-catenin (nuclear/cytoplasmic fractionation and immunoblot), transactivation activity of beta-catenin/T cell factor 4 (TCF4) (luciferase assay with wild-type and mutant TCF4 responsive element), and beta-catenin/TCF4 complex (immunoprecipitation) in human breast cancer cells MDA-MB-231 and T47D.

RESULTS

Troglitazone (TG) down-regulated DNA synthesis in MDA-MB-231 and T47D and decreased mRNA expression of the Wnt co-receptors frizzled-1 and low-density lipoprotein-related protein 6 (LRP6) as well as protein level of LRP6. TG also targets downstream Wnt signaling molecules in T47D cells. TG down-regulates p-beta-catenin (S33/S37/T41) and promotes translocation of beta-catenin into the nucleus. However, TG inhibits beta-catenin-mediated transactivation by down-regulating TCF4 protein levels, thereby inhibiting beta-catenin/TCF4 complex formation. Finally, we found that inhibition of Akt augments TG-mediated down-regulation of DNA synthesis and this result was accompanied with the decreased protein levels of Wnt signaling molecules: LRP6, beta-catenin, and TCF4.

CONCLUSION

These results suggest that the Wnt/beta-catenin signaling pathway, which plays an important role in breast cancer pathogenesis, may be a target for TZD treatment. Moreover, a combination of TZDs and a specific Akt inhibitor may serve as a new approach to target Wnt/beta-catenin directly and via PI3K/Akt action on glycogen synthase-3beta.

Effects of Thiazolidinediones on Differentiation, Proliferation, and Apoptosis

Thiazolidinediones induce adipocyte differentiation and thereby limit proliferative potential; hence, early investigations focused on their ability to modulate cellular proliferation and apoptosis. Several lines of evidence indicate significant thiazolidinedione-mediated antitumor activity. An emerging view is that some antitumor effects are totally or partially peroxisome proliferator-activated receptor-γ (PPARγ) dependent, whereas others are PPARγ independent. The aim of this review is to examine the current evidence about the molecular mechanisms by which thiazolidinediones augment cellular differentiation, inhibit cellular proliferation, and induce apoptosis. We first address the role of thiazolidinediones and/or PPARγ on Wnt/β-catenin signaling pathway as it affects cellular differentiation and then discuss other pathways that are also involved in differentiation as well as proliferation and apoptosis. (Mol Cancer Res 2007;5(6):523–30)

Rosiglitazone sensitizes MDA-MB-231 breast cancer cells to anti-tumour effects of tumour necrosis factor-alpha, CH11 and CYC202

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a member of the nuclear hormone superfamily and has multiple endogenous and pharmacological ligands, including 15-deoxy-Delta (12,14)-prostaglandin J(2) and two thiazolidinediones (TZD), rosiglitazone and pioglitazone, which are used clinically to treat type-2 diabetes mellitus. PPARgamma agonists regulate development, cellular growth and metabolism in various tissues and have been documented to decrease cellular proliferation and to induce apoptosis of various tumour phenotypes, including breast cancer. However, the full spectrum of anti-tumour effects occurs only at suprapharmacological doses. In this study, we investigated the mechanism of rosiglitazone-induced anti-tumour effects of MDA-MB-231 human breast cancer cells, and used that information to predict rosiglitazone-induced sensitization of breast cancer cells to the effects of other compounds. We first confirmed that 100 microM rosiglitazone, but not lower doses, decreases MDA-MB-231 cell viability in vitro. We then used microarray gene expression analysis to determine early rosiglitazone-induced gene expression changes after 4-h exposure, which included 1298 genes that we grouped into functional categories. We selectively confirmed rosiglitazone-mediated effects on expression of key regulators of breast cancer proliferation and apoptosis, including p53, p21 and Bax. Finally, we used this information to predict that rosiglitazone would sensitize MDA-MB-231 cells to the anti-tumour effects of CH11, which trimerizes Fas, as well as tumour necrosis factor-alpha. Moreover, we used the confirmed array data to predict cooperative activity of rosiglitazone and R-roscovitine (CYC202), an inhibitor of multiple cyclin-dependent kinases. We conclude that microarray analysis can determine early TZD-modulated changes in gene expression that help to predict effective in vitro drug combinations.

A study of noise-induced hearing loss and blood pressure in steel mill workers

A cross-sectional study on noise-induced hearing loss and blood pressure was conducted in a steel mill company. Three hundred testees were selected by cluster sampling. They were physically examined and an audiometry was done. Only 151 workers, who had the highest hearing threshold at 4000 Hz and without any family history of hypertension or treatment of drugs on cardiovascular troubles, were selected as subjects in this study. Multiple regression analyses revealed that body mass index, employment duration, age and hearing loss explained a significant amount of variation in systolic and diastolic blood pressure (R2 = 0.16 and 0.12, respectively). There was no significant relationship between hearing loss and blood pressure. In order to adjust confounding factors, analyses of covariances were used and the results suggest that hearing loss is unrelated to blood pressure. It seems that hearing loss is not appropriate as a noise exposure index to measure the relationship between noise exposure and blood pressure.