82 results on '"Christou, H."'
Search Results
2. G566(P) Acetazolamide partially restores pulmonary artery smooth muscle cell de-differentiation in experimental pulmonary hypertension
- Author
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Christodoulou, N, primary, Hudalla, H, additional, Michael, Z, additional, and Christou, H, additional
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- 2020
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3. Lower oxygen saturation targets in preterm infants are not associated with increased rates of pulmonary hypertension.
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Niccum, M., Spyropoulos, F., Levin, J.C., Petty, C.R., Mullen, M.P., and Christou, H.
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OXYGEN saturation ,PREMATURE infants ,PULMONARY hypertension ,BRONCHOPULMONARY dysplasia ,RETROLENTAL fibroplasia - Abstract
BACKGROUND: The optimal oxygen saturation target in preterm infants is not known. In this study, we aimed to assess the effect of lower oxygen saturation targets on the rate of bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and pulmonary hypertension (PH) in preterm infants. METHODS: Retrospective cohort study comparing BPD, ROP, and PH incidence among two cohorts of infants born at≤32 weeks gestation with different oxygen saturation targets at≥34 weeks post-menstrual age (PMA): cohort 1, 94–98% (n = 126); cohort 2, 92–97% (n = 121). Groups compared by Chi-square test, t-test, and multivariable logistic regression. RESULTS: When comparing cohort 1 (average gestational age 29.8 weeks, average birth weight 1271g) with cohort 2 (average gestational age 29.6 weeks, average birth weight 1299g), there was no difference in rate of BPD (24% vs. 19%, p = 0.38), ROP (4% vs. 3%, p = 0.49), or PH (2% vs. 4%, p = 0.44). CONCLUSION: An oxygen saturation target of 92–97% at≥34 weeks PMA was not associated with a higher rate of PH or lower rate of BPD or ROP when compared with a higher target of 94–98%. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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4. Vitamin D and bronchopulmonary dysplasia in preterm infants
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Joung, K E, primary, Burris, H H, additional, Van Marter, L J, additional, McElrath, T F, additional, Michael, Z, additional, Tabatabai, P, additional, Litonjua, A A, additional, Weiss, S T, additional, and Christou, H, additional
- Published
- 2016
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5. Extracellular acidosis alters the metabolic phenotype and susceptibility to apoptosis of pulmonary artery smooth muscle cells
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Geldart, A., primary, Fessenden, J. D., additional, Arons, E., additional, Mitsialis, S. A., additional, Kourembanas, S., additional, and Christou, H., additional
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- 2013
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6. Prediction of Bronchopulmonary Dysplasia by Postnatal Age in Extremely Premature Infants
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Christou, H., primary
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- 2012
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7. Improving Quality of Care for Maternal and Newborn Health: Prospective Pilot Study of the WHO Safe Childbirth Checklist Program
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Christou, H., primary
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- 2012
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8. Dendrimer-Based Postnatal Therapy for Neuroinflammation and Cerebral Palsy in a Rabbit Model
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Christou, H., primary
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- 2012
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9. Inhaled nitric oxide reduces the need for extracorporeal membrane oxygenation in infants with persistent pulmonary hypertension of the newborn.
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Christou, H, Van Marter, L J, Wessel, D L, Allred, E N, Kane, J W, Thompson, J E, Stark, A R, and Kourembanas, S
- Published
- 2000
10. Effect of inhaled nitric oxide on endothelin-1 and cyclic guanosine 5`-monophosphate plasma concentrations in newborn infants with persistent pulmonary hypertension
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Christou, H., Adatia, I., Van Marter, L.J., Kane, J.W., Thompson, J.E., Stark, A.R., Wessel, D.L., and Kourembanas, S.
- Abstract
Objective: To examine the role of endogenous nitric oxide (NO) and endothelin-1 (ET-1) in the pathogenesis of persistent pulmonary hypertension of the newborn (PPHN) and to determine whether inhaled NO, currently under investigation as a new therapy for PPHN, affects plasma concentrations of these vasoactive mediators. Methods: Circulating ET-1 and cyclic guanosine monophosphate (cGMP) concentrations were measured by radioimmunoassay in 15 healthy term newborn infants and 46 newborn infants with PPHN enrolled in a randomized, controlled trial of inhaled NO. These concentrations were followed up longitudinally and compared between the NO and the conventionally treated group. Results: Concentrations of ET-1 were significantly higher and cGMP concentrations significantly lower in infants with PPHN compared with healthy newborn infants (median ET-1, 28 vs 11 pmol/L; p = 0.0001; median cGMP, 35 vs 61 pmol/ml; p = 0.0001, respectively). ET-1 concentrations showed an upward trend at 1 and 24 hours of treatment and a subsequent decline at recovery in both subgroups of patients, with the most pronounced decrease in the NO group. cGMP concentrations increased significantly only in the NO group, with a peak at 1 hour of treatment (median, 61 pmol/ml). As the dose of NO decreased, cGMP concentrations declined. In contrast, conventionally treated infants manifested no change in cGMP concentrations from baseline until recovery, when a significant decrease was noted (median decrease of 13 pmol/ml; p = 0.002). We did not find a significant difference between ET-1 and cGMP concentrations in infants who required extracorporeal membrane oxygenation compared with those who did not. Conclusions: PPHN is associated with increased ET-1 and decreased cGMP plasma concentrations, which may contribute to the pathogenesis of the disease. Inhaled NO appears to modulate these mediators during the disease process, suggesting an interaction between ET-1 and NO in vivo. (J Pediatr 1997;130:603-11)
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- 1997
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11. Carbon monoxide and nitric oxide suppress the hypoxic induction of vascular endothelial growth factor gene via the 5' enhancer.
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Liu, Y, Christou, H, Morita, T, Laughner, E, Semenza, G L, and Kourembanas, S
- Abstract
Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis and blood vessel remodeling. Its expression is up-regulated in vascular smooth muscle cells by a number of conditions, including hypoxia. Hypoxia increases the transcriptional rate of VEGF via a 28-base pair enhancer located in the 5'-upstream region of the gene. The gas molecules nitric oxide (NO) and carbon monoxide (CO) are important vasodilating agents. We report here that these biological molecules can suppress the hypoxia-induced production of VEGF mRNA and protein in smooth muscle cells. In transient expression studies, both NO and CO inhibited the ability of the hypoxic enhancer we have previously identified to activate gene transcription. Furthermore, electrophoretic mobility shift assays indicated decreased binding of hypoxia-inducible factor 1 (HIF-1) to this enhancer by nuclear proteins isolated from CO-treated cells, although HIF-1 protein levels were unaffected by CO. Given that both CO and NO activate guanylyl cyclase to produce cGMP and that a cGMP analog (8-Br-cGMP) showed a similar suppressive effect on the hypoxic induction of the VEGF enhancer, we speculate that the suppression of VEGF by these two gas molecules occurs via a cyclic GMP-mediated pathway.
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- 1998
12. Improving crops’ tolerance to abiotic stresses
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TUBEROSA, ROBERTO, CORAGGIO I., P. CHRISTOU H. KLEE, TUBEROSA R., and CORAGGIO I.
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ABIOTIC STRESS TOLERANCE - Published
- 2004
13. Impact of persistent pulmonary hypertension on cerebral oxygenation in infants with neonatal encephalopathy.
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Rallis D, El-Shibiny H, Szakmar E, Garvey A, Christou H, and El-Dib M
- Abstract
Background: Persistent pulmonary hypertension of the newborn (PPHN) affects systemic oxygenation and may worsen brain injury in infants with neonatal encephalopathy (NE). Evidence suggests that higher cerebral regional oxygenation (crSO
2 ) indicates derangement in cerebral autoregulation, energy metabolism, and blood flow following NE. Our aim was to evaluate the impact of PPHN on crSO2 , in infants with NE treated with therapeutic hypothermia (TH)., Methods: We retrospectively evaluated infants with NE and PPHN vs without PPHN, between 2018-2022. Linear regression analysis was performed to evaluate the impact of PPHN on crSO2 and total MRI score, adjusted for perinatal factors., Results: 164 infants were analyzed, including 19(12%) with PPHN and 145(88%) without. PPHN-infants had significantly higher crSO2 during rewarming and post-rewarming compared to non-PPHN infants (87 ± 6 vs 80 ± 6, p = 0.001; 87 ± 5 vs 80 ± 7, p = 0.008, respectively), and a significantly higher total MRI score [7(2-19) vs 1(0-3), p < 0.001]. PPHN was significantly associated with higher crSO2 during rewarming (b = 6.21, 95% CI 2.37-10.04, p = 0.002) and post-rewarming (b = 8.60, 95% CI 2.28-14.91, p = 0.009), and total MRI score (b = 7.42, 95% CI 4.88-9.95, p < 0.001)., Conclusions: PPHN was associated with higher crSO2 during and after rewarming, and worse brain MRI score, indicating a significant impact of PPHN on brain injury in infants with NE undergoing TH., Impact: Cerebral oxygenation was significantly higher in infants with neonatal encephalopathy (NE) and persistent pulmonary hypertension (PPHN) compared to infants without PPHN, during the rewarming and post-rewarming periods of therapeutic hypothermia (TH). PPHN is associated with brain injury in infants with NE undergoing TH. In infants with NE and PPHN, monitoring of cerebral oxygenation would help detect infants at higher risk of adverse outcomes., (© 2024. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)- Published
- 2024
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14. Stress Granule Assembly in Pulmonary Arterial Hypertension.
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Kosmas K, Papathanasiou AE, Spyropoulos F, Rehman R, Cunha AA, Fredenburgh LE, Perrella MA, and Christou H
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- Animals, Rats, Humans, Male, Oxidative Stress drug effects, Rats, Sprague-Dawley, Disease Models, Animal, Hypertension, Pulmonary metabolism, Hypertension, Pulmonary pathology, Cell Proliferation drug effects, Myocytes, Smooth Muscle metabolism, Myocytes, Smooth Muscle drug effects, Myocytes, Smooth Muscle pathology, Pulmonary Artery pathology, Pulmonary Artery metabolism, Pulmonary Artery drug effects, Pulmonary Arterial Hypertension metabolism, Pulmonary Arterial Hypertension pathology, Stress Granules metabolism
- Abstract
The role of stress granules (SGs) in pulmonary arterial hypertension (PAH) is unknown. We hypothesized that SG formation contributes to abnormal vascular phenotypes, and cardiac and skeletal muscle dysfunction in PAH. Using the rat Sugen/hypoxia (SU/Hx) model of PAH, we demonstrate the formation of SG puncta and increased expression of SG proteins compared to control animals in lungs, right ventricles, and soleus muscles. Acetazolamide (ACTZ) treatment ameliorated the disease and reduced SG formation in all of these tissues. Primary pulmonary artery smooth muscle cells (PASMCs) from diseased animals had increased SG protein expression and SG number after acute oxidative stress and this was ameliorated by ACTZ. Pharmacologic inhibition of SG formation or genetic ablation of the SG assembly protein (G3BP1) altered the SU/Hx-PASMC phenotype by decreasing proliferation, increasing apoptosis and modulating synthetic and contractile marker expression. In human PAH lungs, we found increased SG puncta in pulmonary arteries compared to control lungs and in human PAH-PASMCs we found increased SGs after acute oxidative stress compared to healthy PASMCs. Genetic ablation of G3BP1 in human PAH-PASMCs resulted in a phenotypic switch to a less synthetic and more contractile phenotype. We conclude that increased SG formation in PASMCs and other tissues may contribute to PAH pathogenesis.
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- 2024
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15. Pneumoprotein CC16 in the Umbilical Cord Blood of Preterm Neonates.
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Rallis D, Papathanasiou AE, and Christou H
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- Humans, Infant, Newborn, Retrospective Studies, Female, Male, Respiration, Artificial, Multivariate Analysis, Pregnancy, Biomarkers blood, Fetal Blood chemistry, Fetal Blood metabolism, Bronchopulmonary Dysplasia blood, Uteroglobin blood, Infant, Premature blood, Fetal Membranes, Premature Rupture blood, Gestational Age
- Abstract
Objective: We examined the impact of perinatal factors on cord serum club cell protein (CC16) and the association of CC16 with mechanical ventilation and bronchopulmonary dysplasia (BPD) in preterm neonates., Study Design: A retrospective cohort study including 60 neonates born with gestational age (GA) < 34 weeks. The impact of categorical perinatal factors on cord blood levels of CC16 was examined with univariate and multivariate regression analyses., Results: In neonates with GA < 32 weeks, cord blood CC16 concentrations were significantly lower compared to neonates with GA between 32
0/7 and 336/7 weeks (5.4 ± 2.5 compared to 7.6 ± 2.9 ng/mL, p = 0.039). Neonates with prolonged rupture of membranes had significantly lower CC16 compared to those without prolonged rupture of membranes (4.0 ± 1.9 compared to 7.2 ± 2.2, p < 0.001). Finally, neonates with BPD had significantly lower CC16, compared to neonates without BPD (4.2 ± 2.1 compared to 7.0 ± 2.2 ng/mL, p = 0.004).Prolonged rupture of membranes was significantly negatively associated with CC16 (b = -2.67, 95% confidence interval [CI] -0.49 to -4.85, p = 0.017), after adjusting for GA (b = 0.23, 95% CI 0.03-0.42, p = 0.022), mode of conception, and mode of delivery. Finally, higher CC16 levels were significantly inversely associated with BPD (odds ratio = 0.33, 95% CI 0.12-0.88, p = 0.028), after adjusting for GA (b = 0.27, 95% CI 0.09-0.78, p = 0.015), and birth weight., Conclusion: Prolonged rupture of membranes was significantly negatively associated with cord serum CC16, after adjusting for GA, conception, and delivery mode, and CC16 was significantly inversely associated with BPD, after adjusting for GA and birth weight., Key Points: · Neonates with prolonged rupture of membranes had lower CC16 levels.. · CC16 was significantly negatively associated with BPD.. · CC16 could be a biomarker of lung injury and BPD.., Competing Interests: None declared., (Thieme. All rights reserved.)- Published
- 2024
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16. Changes, Challenges, and Variations in Neonatal-Perinatal Medicine Fellowship: A View from the Program Directors.
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Gray MM, Bruno C, French H, Myers P, Carbajal MM, Reber KM, Christou H, Karpen H, and Johnston LC
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- Humans, United States, Surveys and Questionnaires, Fellowships and Scholarships, Perinatology education, Neonatology education, Education, Medical, Graduate
- Abstract
Objectives: Neonatal-perinatal medicine (NPM) fellowship programs in the United States support >800 learners annually. Understanding variations in the programmatic structure, challenges, and needs is essential to optimize the educational environment and ensure the specialty's future., Study Design: NPM fellowship program directors (PDs) and associate program directors (APDs) were invited to complete an electronic survey on their program administration, recruitment, clinical training, assessment methods, scholarly program, and career pathways. Each participant identified individual programmatic strengths, challenges, opportunities, and threats to the field., Results: Representatives from 59 NPM fellowships provided data (response rate 59/96 = 61%). In total, 30% of PDs received less than the Accreditation Council for Graduate Medical Education -recommended protected time for administrative duties, and 44% of APDs received no protected time. Fellow clinical service assignments varied widely from 13 to 18 months and 90 to 175 call nights over 3 years. Recruitment practices varied across programs; 59% of respondents raised concerns over the pipeline of applicants. Conflicts between fellows and advanced practice providers were identified by 61% of responders. Programs varied in their scholarly offerings, with 44% of NPM fellowships interested in adding broader research opportunities., Conclusion: NPM fellowship leaders identified a need for improved programmatic support, enhanced measures to assess competency, opportunities to strengthen scholarly programs, shared curricular resources, and strategies to balance education with clinical demands. PDs and APDs identified threats to the future of NPM training programs including the diminishing pipeline of applicants into neonatology, challenges with clinical exposure and competence, inadequate support for the educational mission, issues supporting high-quality scholarship, and fewer graduates pursuing physician-investigator pathways. National organizations and academic institutions should take action to address these challenges so that fellowships can optimally prepare graduates to meet their patients' needs., Key Points: · Numerous challenges exist for current program directors in NPM including balancing clinical work with scholarly activities, accurately assessing competency, optimizing the culture of the learning environment, and ensuring that fellows are adequately prepared for a range of postgraduate positions.. · Significant variation exists across NPM fellowship programs in clinical service/calls assigned over 3 years of fellowship training, as well as opportunities to pursue scholarly activities across a variety of areas.. · Challenges exist related to ensuring an adequate number of future applicants into the specialty, including those from backgrounds traditionally underrepresented in medicine, as well as those seeking to pursue careers as physician-investigators.., Competing Interests: M.M.C. is a member of Executive Council for the Organization of Neonatal-Perinatal Training Program Directors (ONTPD). H.E.K. is on the advisory board of Progeny Health and associated as a member of Organization of Neontatal Training Program Directors Executive Committee. L.C.J. is a member of the Organization of Neonatal Training Program Directors (ONTPD) Executive Committee 2017-2021. The other authors reported no conflict of interest., (Thieme. All rights reserved.)
- Published
- 2024
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17. Adult and neonatal models of chemogenetic heart failure caused by oxidative stress.
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Spyropoulos F, Das AA, Waldeck-Weiermair M, Yadav S, Pandey AK, Guo R, Covington TA, Thulabandu V, Kosmas K, Steinhorn B, Perrella MA, Liu X, Christou H, and Michel T
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- Humans, Animals, Mice, Adult, Infant, Newborn, Animals, Newborn, Heart Failure genetics, Heart Failure metabolism, Heart Failure pathology, Oxidative Stress, Disease Models, Animal
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- 2024
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18. Maternal Obesity Modulates Cord Blood Concentrations of Proprotein Convertase Subtilisin/Kexin-type 9 Levels.
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Rallis D, Papathanasiou AE, and Christou H
- Abstract
Context: In utero exposure to maternal obesity or diabetes is considered a pro-inflammatory state., Objective: To evaluate whether cord blood proprotein convertase subtilisin/kexin-type 9 (PCSK9), which is regulated by inflammation and metabolic derangements, is elevated in neonates born to overweight, obese, or diabetic mothers., Methods: A retrospective study in full-term neonates born between 2010 and 2023, at Brigham and Women's Hospital. There were 116 neonates included in our study, of which 74 (64%) were born to overweight/obese mothers and 42 (36%) were born to nonoverweight/nonobese mothers., Results: Neonates born to overweight/obese mothers had significantly higher cord blood concentrations of PCSK9 compared with neonates born to nonoverweight/nonobese group (323 [253-442] ng/mL compared with 270 [244-382] ng/mL, P = .041). We found no significant difference in cord blood concentrations of PCSK9 between neonates of diabetic mothers compared with neonates of nondiabetic mothers. In multivariate linear regression analysis, higher cord plasma PCSK9 concentration was significantly associated with maternal overweight/obesity status (b = 50.12; 95% CI, 4.02-96.22; P = .033), after adjusting for gestational age, birth weight, male sex, and intrauterine growth restriction., Conclusion: Neonates born to mothers with overweight/obesity have higher cord blood PCSK9 concentrations compared with the nonoverweight/nonobese group, and higher cord blood PCSK9 concentrations were significantly associated with maternal overweight/obesity status, after adjusting for perinatal factors. Larger longitudinal studies are needed to examine the role of PCSK9 in the development of metabolic syndrome in high-risk neonates born to overweight, obese, or diabetic mothers., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)
- Published
- 2024
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19. Predictors of successful extubation from volume-targeted ventilation in extremely preterm neonates.
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Rallis D, Ben-David D, Woo K, Robinson J, Beadles D, Spyropoulos F, Christou H, and Cataltepe S
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- Infant, Newborn, Humans, Female, Infant, Retrospective Studies, Respiration, Artificial, Respiration, Infant, Extremely Premature, Airway Extubation
- Abstract
Objective: To identify variables associated with extubation success in extremely preterm neonates extubated from invasive volume-targeted ventilation., Study Design: We retrospectively evaluated 84 neonates ≤28 weeks' gestational age, on their first elective extubation. The primary outcome of successful extubation was defined as non-reintubation within seven days. We used multivariate logistic regression analysis., Results: We identified 58 (69%) neonates (mean gestational age of 26.5 ± 1.4 weeks, birthweight 921 ± 217 g) who met the primary outcome. Female sex (OR 1.15, 95% CI 1.01-9.10), higher pre-extubation weight (OR 1.29, 95% CI 1.05-1.59), and pH (OR 2.54, 95% CI 1.54-4.19), and lower pre-extubation mean airway pressure (MAP) (OR 0.49, 95% CI 0.33-0.73) were associated with successful extubation., Conclusions: In preterm neonates, female sex, higher pre-extubation weight and pH, and lower pre-extubation MAP were predictors of successful extubation from volume-targeted ventilation. Evaluation of these variables will likely assist clinicians in selecting the optimal time for extubation in such vulnerable neonates., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)
- Published
- 2024
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20. Single center experience with first-intention high-frequency jet vs. volume-targeted ventilation in extremely preterm neonates.
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Rallis D, Ben-David D, Woo K, Robinson J, Beadles D, Bernardini L, Abdulhayoglu E, Flanigan E, and Christou H
- Abstract
Objectives: To examine whether first-intention high-frequency jet ventilation (HFVJ), compared to volume-targeted ventilation (VTV), in extremely preterm infants is associated with lower incidence of bronchopulmonary dysplasia (BPD) and other adverse clinical outcomes., Study Design: We conducted a retrospective cohort study evaluating neonates with gestational age (GA) ≤28 weeks, who received first-intention HFJV (main exposure) or VTV (comparator), between 11/2020 and 3/2023, with a subgroup analysis including neonates with GA ≤26 weeks and oxygenation index (OI) >5., Results: We identified 117 extremely preterm neonates, 24 (GA 25.2 ± 1.6 weeks) on HFJV, and 93 (GA 26.4 ± 1.5 weeks, p = 0.001) on VTV. The neonates in the HFJV group had higher oxygenation indices on admission, higher inotrope use, and remained intubated for a longer period. Despite these differences, there were no statistically significant differences in rates of BPD, survival, or other adverse outcomes between the two groups. In subgroup analysis of 18 neonates on HFJV and 39 neonates on VTV, no differences were recorded in the GA, and duration of mechanical ventilation, while neonates in the HFJV group had significantly lower rates of BPD (50% compared to 83%, p = 0.034), and no significant differences in other adverse outcomes compared to neonates in the VTV group. In neonates ≤26 weeks of GA with OI >5, HFJV was significantly associated with lower rates of BPD (OR 0.21, 95% CI 0.05-0.92), and combined BPD or death (OR 0.18, 95% CI 0.03-0.85), after adjusting for birth weight, and Arterial-alveolar gradient on admission., Conclusions: In extremely preterm neonates ≤26 weeks of GA with OI >5, first-intention HFJV, in comparison to VTV, is associated with lower rates of BPD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Rallis, Ben-David, Woo, Robinson, Beadles, Bernardini, Abdulhayoglu, Flanigan and Christou.)
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- 2024
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21. Proceedings of the 14th International Newborn Brain Conference: Other forms of brain monitoring, such as NIRS, fMRI, biochemical, etc.
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Ali S, Altamimi T, Annink K, Bartmann P, Beato N, Belker K, Ben-David D, Benders M, Bhattacharya S, Anbu Chakkarapani A, Anbu Chakkarapani A, Charbonneau L, Cherkerzian S, Chowdhury RA, Christou H, de Ribaupierre D, Dehaes M, Domogalla C, Duerden EG, El-Dib M, Elanbari M, Elshibiny H, Engel C, Felderhoff U, Flemmer AW, Franceschini MA, Franz A, Garvey A, Groenendaal F, Gupta S, Hannon K, Hellström-Westas L, Herber-Jonat S, Holz S, Hüning B, Inder T, Jamil A, Jilson T, Kebaya LMN, Keller M, Khalifa AKM, Kim SH, Kittel J, Koch L, Kowalczyk A, Kühr J, St Lawrence K, Lee S, Marandyuk B, Marlow N, Mayorga PC, Meyer R, Meyerink P, Miró J, More K, Munk A, Munster C, Musabi M, Nuyt AM, Peters J, Plum A, Poirier N, Pöschl J, Raboisson MJ, Robinson J, Roychaudhuri S, Rüdiger M, Sarközy G, Saugstad OD, Segerer H, Soni N, Stein A, Steins-Rang C, Sunwoo J, Szakmar E, Tang L, Taskin E, Vahidi H, Waldherr S, Wieg C, Winkler S, Wu R, Yajamanyam PK, and Yapicioglu-Yildizdas H
- Published
- 2023
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22. Maternal diabetes and the role of neonatal reticulocyte hemoglobin content as a biomarker of iron status in the perinatal period.
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Babacheva E, Rallis D, Christou H, Mitsiakos G, Mikos T, Dampala K, Tsakalidis C, Kioumi A, Goulis DG, and Soubasi V
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- Pregnancy, Infant, Infant, Newborn, Female, Humans, Reticulocytes, Iron, Prospective Studies, Hemoglobins, Ferritins, Biomarkers, Diabetes, Gestational, Obesity, Maternal, Pre-Eclampsia, Iron Deficiencies
- Abstract
Aims: We aimed to evaluate the effects of maternal diabetes on neonatal iron status, measuring erythrocyte indices including hemoglobin, hematocrit, reticulocytes, mean corpuscular volume (MCV), percent (%) hypochromia, ferritin, and additionally mean reticulocyte hemoglobin content (MCHr) as an early marker of iron deficiency, and examine the association between neonatal MCHr, red cell indices, and ferritin., Materials and Methods: We conducted a hospital-based prospective cohort study in a tertiary neonatal unit of a University Hospital from 2018 to 2020. We enrolled 126 maternal-infant pairs of mothers whose pregnancy was associated with diabetes and 74 maternal-infant pairs from uncomplicated pregnancies. Erythrocyte indices were analyzed within the first twelve hours after birth. Erythrocyte parameters were compared between infants of the diabetes and the non-diabetic group. We examined the correlation of the neonatal MCHr with perinatal characteristics, including gestation, birth weight, maternal body mass index, the erythrocytic indices, maternal diabetes, maternal obesity, prematurity, small-for-gestational-age status, maternal preeclampsia, and maternal anemia. Finally, we evaluated the discordance between neonatal MCHr and neonatal ferritin., Results: Infants of the diabetes group had a significantly lower MCHr (32.6 pg vs. 34.2 pg, p=0.003) compared with infants of uncomplicated pregnancies. Neonatal MCHr was significantly correlated with maternal hypochromia (r=-0.237, p=0.004) and neonatal MCV (r=0.674, p<0.001). Neonatal MCHr was significantly associated with maternal diabetes [standardized coefficients 0.21, 95% confidence interval (CI) 0.05-0.58, p=0.003) and maternal preeclampsia (standardized coefficients 0.17, 95% CI 0.02-0.92, p=0.019), after adjusting for maternal anemia, maternal obesity, prematurity, and small-for-gestational-age status. Those results were consistent also when analyzing maternal-infant pairs with pre-existing diabetes, and maternal-infant pairs with gestational diabetes. There was significant discordance between neonatal MCHr and neonatal ferritin (p=0.001)., Conclusions: MCHr was significantly lower in infants of mothers whose pregnancy was associated with diabetes compared with infants of non-diabetic mothers and correlated with neonatal and maternal red cell indices of iron deficiency. Since there was significant discordance between neonatal MCHr and ferritin during the first postnatal day, it is possible that MCHr could be used as a screening test for iron deficiency, especially in infants., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Babacheva, Rallis, Christou, Mitsiakos, Mikos, Dampala, Tsakalidis, Kioumi, Goulis and Soubasi.)
- Published
- 2022
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23. Skeletal Muscle Dysfunction in Experimental Pulmonary Hypertension.
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Kosmas K, Michael Z, Papathanasiou AE, Spyropoulos F, Adib E, Jasuja R, and Christou H
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- Animals, Muscle Fibers, Fast-Twitch, Muscle Fibers, Skeletal, Muscle, Skeletal physiology, Rats, Hypertension, Pulmonary, Physical Conditioning, Animal
- Abstract
Pulmonary arterial hypertension (PAH) is a serious, progressive, and often fatal disease that is in urgent need of improved therapies that treat it. One of the remaining therapeutic challenges is the increasingly recognized skeletal muscle dysfunction that interferes with exercise tolerance. Here we report that in the adult rat Sugen/hypoxia (SU/Hx) model of severe pulmonary hypertension (PH), there is highly significant, almost 50%, decrease in exercise endurance, and this is associated with a 25% increase in the abundance of type II muscle fiber markers, thick sarcomeric aggregates and an increase in the levels of FoxO1 in the soleus (a predominantly type I fiber muscle), with additional alterations in the transcriptomic profiles of the diaphragm (a mixed fiber muscle) and the extensor digitorum longus (a predominantly Type II fiber muscle). In addition, soleus atrophy may contribute to impaired exercise endurance. Studies in L6 rat myoblasts have showed that myotube differentiation is associated with increased FoxO1 levels and type II fiber markers, while the inhibition of FoxO1 leads to increased type I fiber markers. We conclude that the formation of aggregates and a FoxO1-mediated shift in the skeletal muscle fiber-type specification may underlie skeletal muscle dysfunction in an experimental study of PH.
- Published
- 2022
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24. Mechanisms of pulmonary vascular dysfunction in pulmonary hypertension and implications for novel therapies.
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Christou H and Khalil RA
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- Cell Proliferation, Humans, Muscle, Smooth, Vascular, Myocytes, Smooth Muscle metabolism, Pulmonary Artery, Vascular Remodeling, Vasoconstriction, Hypertension, Pulmonary
- Abstract
Pulmonary hypertension (PH) is a serious disease characterized by various degrees of pulmonary vasoconstriction and progressive fibroproliferative remodeling and inflammation of the pulmonary arterioles that lead to increased pulmonary vascular resistance, right ventricular hypertrophy, and failure. Pulmonary vascular tone is regulated by a balance between vasoconstrictor and vasodilator mediators, and a shift in this balance to vasoconstriction is an important component of PH pathology, Therefore, the mainstay of current pharmacological therapies centers on pulmonary vasodilation methodologies that either enhance vasodilator mechanisms such as the NO-cGMP and prostacyclin-cAMP pathways and/or inhibit vasoconstrictor mechanisms such as the endothelin-1, cytosolic Ca
2+ , and Rho-kinase pathways. However, in addition to the increased vascular tone, many patients have a "fixed" component in their disease that involves altered biology of various cells in the pulmonary vascular wall, excessive pulmonary artery remodeling, and perivascular fibrosis and inflammation. Pulmonary arterial smooth muscle cell (PASMC) phenotypic switch from a contractile to a synthetic and proliferative phenotype is an important factor in pulmonary artery remodeling. Although current vasodilator therapies also have some antiproliferative effects on PASMCs, they are not universally successful in halting PH progression and increasing survival. Mild acidification and other novel approaches that aim to reverse the resident pulmonary vascular pathology and structural remodeling and restore a contractile PASMC phenotype could ameliorate vascular remodeling and enhance the responsiveness of PH to vasodilator therapies.- Published
- 2022
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25. Pleiotropic Effects of Pyruvate Kinase M2 in Right Ventricular Failure and Pulmonary Arterial Hypertension.
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Christou H
- Abstract
Competing Interests: The author has reported that she has no relationships relevant to the contents of this paper to disclose.
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- 2022
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26. Metabolomic and transcriptomic signatures of chemogenetic heart failure.
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Spyropoulos F, Sorrentino A, van der Reest J, Yang P, Waldeck-Weiermair M, Steinhorn B, Eroglu E, Saeedi Saravi SS, Yu P, Haigis M, Christou H, and Michel T
- Subjects
- Alanine pharmacology, Amino Acids metabolism, Amino Acids pharmacology, Amino Acids therapeutic use, Animals, Dependovirus metabolism, Disease Models, Animal, Hydrogen Peroxide metabolism, Myocytes, Cardiac metabolism, Oxidative Stress, Rats, Transcriptome, Cardiomyopathy, Dilated metabolism, Heart Failure genetics, Heart Failure metabolism
- Abstract
The failing heart is characterized by elevated levels of reactive oxygen species. We have developed an animal model of heart failure induced by chemogenetic production of oxidative stress in the heart using a recombinant adeno-associated virus (AAV9) expressing yeast d-amino acid oxidase (DAAO) targeted to cardiac myocytes. When DAAO-infected animals are fed the DAAO substrate d-alanine, the enzyme generates hydrogen peroxide (H
2 O2 ) in the cardiac myocytes, leading to dilated cardiomyopathy. However, the underlying mechanisms of oxidative stress-induced heart failure remain incompletely understood. Therefore, we investigated the effects of chronic oxidative stress on the cardiac transcriptome and metabolome. Rats infected with recombinant cardiotropic AAV9 expressing DAAO or control AAV9 were treated for 7 wk with d-alanine to stimulate chemogenetic H2 O2 production by DAAO and generate dilated cardiomyopathy. After hemodynamic assessment, left and right ventricular tissues were processed for RNA sequencing and metabolomic profiling. DAAO-induced dilated cardiomyopathy was characterized by marked changes in the cardiac transcriptome and metabolome both in the left and right ventricle. Downregulated transcripts are related to energy metabolism and mitochondrial function, accompanied by striking alterations in metabolites involved in cardiac energetics, redox homeostasis, and amino acid metabolism. Upregulated transcripts are involved in cytoskeletal organization and extracellular matrix. Finally, we noted increased metabolite levels of antioxidants glutathione and ascorbate. These findings provide evidence that chemogenetic generation of oxidative stress leads to a robust heart failure model with distinct transcriptomic and metabolomic signatures and set the basis for understanding the underlying pathophysiology of chronic oxidative stress in the heart. NEW & NOTEWORTHY We have developed a "chemogenetic" heart failure animal model that recapitulates a central feature of human heart failure: increased cardiac redox stress. We used a recombinant DAAO enzyme to generate H2 O2 in cardiomyocytes, leading to cardiomyopathy. Here we report striking changes in the cardiac metabolome and transcriptome following chemogenetic heart failure, similar to changes observed in human heart failure. Our findings help validate chemogenetic approaches for the discovery of novel therapeutic targets in heart failure.- Published
- 2022
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27. ETV2 regulates PARP-1 binding protein to induce ER stress-mediated death in tuberin-deficient cells.
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Shrestha S, Lamattina A, Pacheco-Rodriguez G, Ng J, Liu X, Sonawane A, Imani J, Qiu W, Kosmas K, Louis P, Hentschel A, Steagall WK, Onishi R, Christou H, Henske EP, Glass K, Perrella MA, Moss J, Tantisira K, and El-Chemaly S
- Subjects
- DNA-Binding Proteins genetics, Endoplasmic Reticulum Stress, Humans, Mechanistic Target of Rapamycin Complex 1 metabolism, Transcription Factors genetics, Tuberous Sclerosis Complex 2 Protein genetics, Tumor Suppressor Proteins genetics, Tumor Suppressor Proteins metabolism, Lymphangioleiomyomatosis drug therapy, Lymphangioleiomyomatosis genetics, Lymphangioleiomyomatosis metabolism, Poly(ADP-ribose) Polymerase Inhibitors therapeutic use
- Abstract
Lymphangioleiomyomatosis (LAM) is a rare progressive disease, characterized by mutations in the tuberous sclerosis complex genes ( TSC1 or TSC2 ) and hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1). Here, we report that E26 transformation-specific (ETS) variant transcription factor 2 (ETV2) is a critical regulator of Tsc2 -deficient cell survival. ETV2 nuclear localization in Tsc2 -deficient cells is mTORC1-independent and is enhanced by spleen tyrosine kinase (Syk) inhibition. In the nucleus, ETV2 transcriptionally regulates poly(ADP-ribose) polymerase 1 binding protein (PARPBP) mRNA and protein expression, partially reversing the observed down-regulation of PARPBP expression induced by mTORC1 blockade during treatment with both Syk and mTORC1 inhibitors. In addition, silencing Etv2 or Parpbp in Tsc2 -deficient cells induced ER stress and increased cell death in vitro and in vivo. We also found ETV2 expression in human cells with loss of heterozygosity for TSC2 , lending support to the translational relevance of our findings. In conclusion, we report a novel ETV2 signaling axis unique to Syk inhibition that promotes a cytocidal response in Tsc2 -deficient cells and therefore maybe a potential alternative therapeutic target in LAM., (© 2022 Shrestha et al.)
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- 2022
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28. Proceedings of the 13th International Newborn Brain Conference: Neonatal Neurocritical Care, Seizures, and Continuous EEG monitoring.
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Abend N, Adams E, Al Balushi A, Alburaki W, Appendino J, Barbosa VS, Birca A, Bonifacio S, Branagan A, Chang T, Chowdhury R, Christou H, Chu C, Cilio MR, Comani S, Corsi-Cabrera M, Croce P, Cubero-Rego L, Dawoud F, de Vries L, Dehaes M, Devane D, Duncan A, El Ters N, El-Dib M, Elshibiny H, Esser M, Fairchild K, Finucane E, Franceschini MA, Gallagher A, Ghosh A, Glass H, Venkata SKRG, Baillet TH, Herzberg E, Hildrey E, Hurley T, Inder T, Jacobs E, Jefferies K, Jermendy A, Khazaei M, Kilmartin K, King G, Lauronen L, Lee S, Leijser L, Lind J, Llaguno NS, Machie M, Magalhães M, Mahdi Z, Maluomi J, Marandyuk B, Massey S, McCulloch C, Metsäranta M, Mikkonen K, Mohammad K, Molloy E, Momin S, Munster C, Murthy P, Netto A, Nevalainen P, Nguyen J, Nieves M, Nyman J, Oliver N, Peeters C, Pietrobom RFR, Pijpers J, Pinchefksy E, Ping YB, Quirke F, Raeisi K, Ricardo-Garcell J, Robinson J, Rodrigues DP, Rosati J, Scott J, Scringer-Wilkes M, Shellhaas R, Smit L, Soul J, Srivastava A, Steggerda S, Sunwoo J, Szakmar E, Tamburro G, Thomas S, Toiviainen-Salo S, Toma AI, Vanhatalo S, Variane GFT, Vein A, Vesoulis Z, Vilan A, Volpe J, Weeke L, Wintermark P, Wusthoff C, Zappasodi F, Zein H, and Zempel J
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- Electroencephalography, Humans, Infant, Newborn, Monitoring, Physiologic, Brain, Seizures therapy
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- 2022
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29. Off-label use of PAH-targeted medications approved for adults and their financial coverage by health insurances are vital for children with pulmonary hypertension.
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Hansmann G, Christou H, Koestenberger M, and Sallmon H
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- Adult, Child, Humans, Insurance, Health, Observational Studies as Topic, Randomized Controlled Trials as Topic, Antihypertensive Agents therapeutic use, Hypertension, Pulmonary drug therapy, Off-Label Use
- Published
- 2021
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30. Acetazolamide Improves Right Ventricular Function and Metabolic Gene Dysregulation in Experimental Pulmonary Arterial Hypertension.
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Spyropoulos F, Michael Z, Finander B, Vitali S, Kosmas K, Zymaris P, Kalish BT, Kourembanas S, and Christou H
- Abstract
Background: Right ventricular (RV) performance is a key determinant of mortality in pulmonary arterial hypertension (PAH). RV failure is characterized by metabolic dysregulation with unbalanced anaerobic glycolysis, oxidative phosphorylation, and fatty acid oxidation (FAO). We previously found that acetazolamide (ACTZ) treatment modulates the pulmonary inflammatory response and ameliorates experimental PAH. Objective: To evaluate the effect of ACTZ treatment on RV function and metabolic profile in experimental PAH. Design/Methods: In the Sugen 5416/hypoxia (SuHx) rat model of severe PAH, RV transcriptomic analysis was performed by RNA-seq, and top metabolic targets were validated by RT-PCR. We assessed the effect of therapeutic administration of ACTZ in the drinking water on hemodynamics by catheterization [right and left ventricular systolic pressure (RVSP and LVSP, respectively)] and echocardiography [pulmonary artery acceleration time (PAAT), RV wall thickness in diastole (RVWT), RV end-diastolic diameter (RVEDD), tricuspid annular plane systolic excursion (TAPSE)] and on RV hypertrophy (RVH) by Fulton's index (FI) and RV-to-body weight (BW) ratio (RV/BW). We also examined myocardial histopathology and expression of metabolic markers in RV tissues. Results: There was a distinct transcriptomic signature of RVH in the SuHx model of PAH, with significant downregulation of metabolic enzymes involved in fatty acid transport, beta oxidation, and glucose oxidation compared to controls. Treatment with ACTZ led to a pattern of gene expression suggestive of restored metabolic balance in the RV with significantly increased beta oxidation transcripts. In addition, the FAO transcription factor peroxisome proliferator-activated receptor gamma coactivator 1-alpha ( Pgc-1 α) was significantly downregulated in untreated SuHx rats compared to controls, and ACTZ treatment restored its expression levels. These metabolic changes were associated with amelioration of the hemodynamic and echocardiographic markers of RVH in the ACTZ-treated SuHx animals and attenuation of cardiomyocyte hypertrophy and RV fibrosis. Conclusion: Acetazolamide treatment prevents the development of PAH, RVH, and fibrosis in the SuHx rat model of severe PAH, improves RV function, and restores the RV metabolic profile., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Spyropoulos, Michael, Finander, Vitali, Kosmas, Zymaris, Kalish, Kourembanas and Christou.)
- Published
- 2021
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31. Carbonic anhydrase inhibition improves pulmonary artery reactivity and nitric oxide-mediated relaxation in sugen-hypoxia model of pulmonary hypertension.
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Christou H, Michael Z, Spyropoulos F, Chen Y, Rong D, and Khalil RA
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- Animals, Hypoxia physiopathology, Male, Mesenteric Arteries physiopathology, Nitric Oxide metabolism, Nitric Oxide pharmacology, Rats, Sprague-Dawley, Vasodilation drug effects, Rats, Carbonic Anhydrase Inhibitors pharmacology, Hypertension, Pulmonary physiopathology, Muscle, Smooth, Vascular physiopathology, Pulmonary Artery physiopathology
- Abstract
Pulmonary hypertension (PH) is a serious disease with pulmonary arterial fibrotic remodeling and limited responsiveness to vasodilators. Our data suggest that mild acidosis induced by carbonic anhydrase inhibition could ameliorate PH, but the vascular mechanisms are unclear. We tested the hypothesis that carbonic anhydrase inhibition ameliorates PH by improving pulmonary vascular reactivity and relaxation mechanisms. Male Sprague-Dawley rats were either control normoxic (Nx), or injected with Sugen 5416 (20 mg/kg, sc) and subjected to hypoxia (9% O
2 ) (Su + Hx), or Su + Hx treated with acetazolamide (ACTZ, 100 mg/kg/day, in drinking water). After measuring the hemodynamics, right ventricular hypertrophy was assessed by Fulton's Index; vascular function was measured in pulmonary artery, aorta, and mesenteric arteries; and pulmonary arteriolar remodeling was assessed in lung sections. Right ventricular systolic pressure and Fulton's Index were increased in Su + Hx and reduced in Su + Hx + ACTZ rats. Pulmonary artery contraction to KCl and phenylephrine were reduced in Su + Hx and improved in Su + Hx + ACTZ. Acetylcholine (ACh)-induced relaxation and nitrate/nitrite production were reduced in pulmonary artery of Su + Hx and improved in Su + Hx + ACTZ. ACh relaxation was blocked by nitric oxide (NO) synthase and guanylate cyclase inhibitors, supporting a role of NO-cGMP. Sodium nitroprusside (SNP)-induced relaxation was reduced in pulmonary artery of Su + Hx, and ACTZ enhanced relaxation to SNP. Contraction/relaxation were not different in aorta or mesenteric arteries of all groups. Pulmonary arterioles showed wall thickening in Su + Hx that was ameliorated in Su + Hx + ACTZ. Thus, amelioration of pulmonary hemodynamics during carbonic anhydrase inhibition involves improved pulmonary artery reactivity and NO-mediated relaxation and may enhance responsiveness to vasodilator therapies in PH.- Published
- 2021
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32. Adipokines and Metabolic Regulators in Human and Experimental Pulmonary Arterial Hypertension.
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Papathanasiou AE, Spyropoulos F, Michael Z, Joung KE, Briana DD, Malamitsi-Puchner A, Mantzoros CS, and Christou H
- Subjects
- Adult, Animals, Case-Control Studies, Female, Glycolysis, Hemodynamics, Humans, Hypertension, Pulmonary metabolism, Male, Middle Aged, Rats, Rats, Sprague-Dawley, Young Adult, Adipokines metabolism, Adiponectin blood, Fatty Acid-Binding Proteins blood, Fibroblast Growth Factors blood, PPAR gamma blood, Pulmonary Arterial Hypertension metabolism
- Abstract
Pulmonary hypertension (PH) is associated with meta-inflammation related to obesity but the role of adipose tissue in PH pathogenesis is unknown. We hypothesized that adipose tissue-derived metabolic regulators are altered in human and experimental PH. We measured circulating levels of fatty acid binding protein 4 (FABP-4), fibroblast growth factor -21 (FGF-21), adiponectin, and the mRNA levels of FABP-4, FGF-21, and peroxisome proliferator-activated receptor γ (PPARγ) in lung tissue of patients with idiopathic PH and healthy controls. We also evaluated lung and adipose tissue expression of these mediators in the three most commonly used experimental rodent models of pulmonary hypertension. Circulating levels of FABP-4, FGF-21, and adiponectin were significantly elevated in PH patients compared to controls and the mRNA levels of these regulators and PPARγ were also significantly increased in human PH lungs and in the lungs of rats with experimental PH compared to controls. These findings were coupled with increased levels of adipose tissue mRNA of genes related to glucose uptake, glycolysis, tricarboxylic acid cycle, and fatty acid oxidation in experimental PH. Our results support that metabolic alterations in human PH are recapitulated in rodent models of the disease and suggest that adipose tissue may contribute to PH pathogenesis.
- Published
- 2021
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33. Echocardiographic markers of pulmonary hemodynamics and right ventricular hypertrophy in rat models of pulmonary hypertension.
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Spyropoulos F, Vitali SH, Touma M, Rose CD, Petty CR, Levy P, Kourembanas S, and Christou H
- Abstract
Echocardiography is the gold standard non-invasive technique to diagnose pulmonary hypertension. It is also an important modality used to monitor disease progression and response to treatment in patients with pulmonary hypertension. Surprisingly, only few studies have been conducted to validate and standardize echocardiographic parameters in experimental animal models of pulmonary hypertension. We sought to define cut-off values for both invasive and non-invasive measures of pulmonary hemodynamics and right ventricular hypertrophy that would reliably diagnose pulmonary hypertension in three different rat models. The study was designed in two phases: (1) a derivation phase to establish the cut-off values for invasive measures of right ventricular systolic pressure, Fulton's index (right ventricular weight/left ventricle + septum weight), right ventricular to body weight ratio, and non-invasive echocardiographic measures of pulmonary arterial acceleration time, pulmonary arterial acceleration time to ejection time ratio and right ventricular wall thickness in diastole in the hypoxic and monocrotaline rat models of pulmonary hypertension and (2) a validation phase to test the performance of the cut-off values in predicting pulmonary hypertension in an independent cohort of rats with Sugen/hypoxia-induced pulmonary hypertension. Our study demonstrates that right ventricular systolic pressure ≥35.5 mmHg and Fulton's Index ≥0.34 are highly sensitive (>94%) and specific (>91%) cut-offs to distinguish animals with pulmonary hypertension from controls. When pulmonary arterial acceleration time/ejection time and right ventricular wall thickness in diastole were both measured, a result of either pulmonary arterial acceleration time/ejection time ≤0.25 or right ventricular wall thickness in diastole ≥1.03 mm detected right ventricular systolic pressure ≥35.5 mmHg or Fulton's Index ≥0.34 with a sensitivity of 88% and specificity of 100%. With properly validated non-invasive echocardiography measures of right ventricular performance in rats that accurately predict invasive measures of pulmonary hemodynamics, future studies can now utilize these markers to test the efficacy of different treatments with preclinical therapeutic modeling., (© The Author(s) 2020.)
- Published
- 2020
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34. Association of circulating FGF-21 levels in the first week of life and postnatal growth in hospitalized preterm infants.
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Joung KE, Clausen D, Herdt A, Presti A, Snyder R, Peters C, Christou H, and Mantzoros CS
- Abstract
Background: The role of fetal and neonatal growth in the development of adult-onset diseases such as obesity and metabolic syndrome has become increasingly appreciated. Fibroblast growth factor-21 (FGF-21) is known as a regulator of glucose and lipid metabolism. FGF-21 levels are elevated in obese adults and children. The role of FGF-21 in neonatal growth in preterm infants is not known., Objectives: We aimed to evaluate the association of circulating FGF-21 levels in the first week of life and neonatal growth parameters at the time of discharge from NICU., Methods: We performed a longitudinal study of 25 preterm neonates admitted to NICU. Blood samples were collected at two time points: within 24 h of life (T1), and 24-96 h after the first blood draw (T2). FGF-21 levels were measured in plasma by ELISA. Weight, length, BMI and their Z-scores were measured at the time of birth and discharge., Results: The FGF-21 levels were significantly higher at T2 than at T1 (p < 0.001). FGF-21 levels at both time points were positively correlated with gestational age (r = 0.43, p = 0.03). FGF-21 at T1 was positively associated with weight Z-score (β = 0.19, p = 0.001) and length Z-score at discharge (β = 0.21, p = 0.03)., Conclusions: Circulating FGF-21 levels increase significantly in the first week, and the FGF-21 levels within the first 24 h are positively associated with weight and length Z-scores at discharge in preterm infants. These results suggest that FGF-21 may be involved in growth and developmental maturation., Competing Interests: Authors have no conflicts of interests., (© 2020 Published by Elsevier Inc.)
- Published
- 2020
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35. GLYCOSYLATED FIBRONECTIN AND INHIBIN ARE LOWER AND ANTI-MÜLLERIAN HORMONE IS HIGHER IN UMBILICAL CORD BLOOD WHEN MOTHERS HAVE PREECLAMPSIA.
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DiPrisco B, Kumar A, Kalra B, Savjani GV, Michael Z, Farr O, Papathanasiou AE, Christou H, and Mantzoros CS
- Subjects
- Anti-Mullerian Hormone, Boston, Case-Control Studies, Female, Fetal Blood, Fibronectins, Glycation End Products, Advanced, Humans, Infant, Newborn, Inhibins, Male, Mothers, Pregnancy, Pre-Eclampsia
- Abstract
Objective: Preeclampsia is a common disorder of pregnancy, causing significant morbidity and mortality for mothers and infants. Several molecules, including glycosylated fibronectin (GlyFn), the inhibin-related proteins, anti-müllerian hormone (AMH), and the insulin-like growth factor axis, are altered in maternal plasma in the setting of preeclampsia; however, these molecules have not been previously measured in cord blood of infants born to mothers with preeclampsia, which may represent changes in fetal physiology. We evaluated potential biomarkers of preeclampsia in umbilical cord blood to fill the gap in knowledge. Methods: This is a case-control study of 196 neonates born at a tertiary teaching hospital in Boston from 2010-2017. Forty-nine neonates born to mothers with preeclampsia were matched 1:3 by gestational age, sex, and birth weight z -score with 147 controls. Eleven analytes were measured in cord blood by enzyme-linked immunosorbent assay. Binary logistic regression analyses were performed to evaluate associations between preeclampsia and analytes. Results: Mean cord blood levels of GlyFn and total inhibin were significantly lower in neonates born to mothers with preeclampsia compared to controls, and AMH levels were significantly higher in males born to mothers with preeclampsia than male controls. Associations remained significant after controlling for maternal and neonatal characteristics. Conclusion: Cord blood levels of GlyFn and inhibin are decreased and AMH (male) levels are increased in infants of preeclamptic mothers, which is opposite the pattern these biomarkers show in serum of mothers with preeclampsia. These molecules may be important in the pathophysiology and long-term effects of preeclampsia on the developing fetus. Abbreviations: AMH = anti-müllerian hormone; ELISA = enzyme-linked immunosorbent assay; GlyFn = glycosylated fibronectin; IGF = insulin-like growth factor; IGFBP5 = insulin-like growth factor binding protein 5; LOD = limit of detection; PAPP-A = pregnancy-associated plasma protein A; PAPP-A2 = pregnancy-associated plasma protein A2.
- Published
- 2020
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36. Placental proteases PAPP-A and PAPP-A2, the binding proteins they cleave (IGFBP-4 and -5), and IGF-I and IGF-II: Levels in umbilical cord blood and associations with birth weight and length.
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DiPrisco B, Kumar A, Kalra B, Savjani GV, Michael Z, Farr O, Papathanasiou AE, Christou H, and Mantzoros C
- Subjects
- Case-Control Studies, Female, Humans, Infant, Newborn, Isoenzymes chemistry, Pregnancy, Pregnancy-Associated Plasma Protein-A chemistry, Protein Binding, Proteolysis, Insulin-Like Growth Factor Binding Protein 4 metabolism, Insulin-Like Growth Factor Binding Protein 5 metabolism, Insulin-Like Growth Factor I metabolism, Insulin-Like Growth Factor II metabolism, Isoenzymes metabolism, Placenta enzymology, Pregnancy-Associated Plasma Protein-A metabolism
- Abstract
Background: A newborn's birth weight for gestational age provides important insights into his or her fetal growth and well-being. While the underlying mechanisms regulating fetal growth remain to be fully elucidated, the IGF axis plays an important role. Some components of this axis have been well-characterized in umbilical cord blood, but others have not yet been studied. We measured the proteases PAPP-A and PAPP-A2, the binding proteins they cleave (IGFBP-4 and -5), and the established molecules IGF-I and -II in umbilical cord blood to better characterize the IGF axis in relation to birth weight and length., Methods: We performed a case-control study of 180 neonates born at a tertiary teaching hospital in Boston. To maximize power, infants were recruited in a 1:3:1 ratio with 37 SGA, 111 AGA, and 37 LGA infants matched by gestational age, sex, and delivery mode. IGF-I, IGF-II, IGFBP-4, IGFBP-5, PAPP-A, and PAPP-A2 were measured in umbilical cord blood by ELISA. Associations between birth weight and birth length Z-scores and the Z-scores of the above molecules were analyzed using linear regression models and analysis of covariance., Results: Birth weight and length Z-scores were positively associated with Z-scores of IGF-I, IGF-II, total IGFBP-4, and IGFBP-5, with IGF-I having the strongest association. Birth weight and length Z-scores were negatively associated with Z-scores of intact IGFBP-4, PAPP-A, and PAPP-A2 levels., Conclusions: We confirm previous findings of significant associations between the IGFs in cord blood and newborn size and for the first time show positive associations between cord blood total IGFBP-4 and -5 and birth weight and a negative association between intact IGFBP-4 and birth weight. We also show for the first time a reciprocal relationship between cord blood levels of PAPP-A and PAPP-A2 and newborn size. The implications of these findings need to be further examined in large longitudinal studies and likely have diagnostic and therapeutic potential., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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37. Carbonic Anhydrase Inhibition Ameliorates Inflammation and Experimental Pulmonary Hypertension.
- Author
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Hudalla H, Michael Z, Christodoulou N, Willis GR, Fernandez-Gonzalez A, Filatava EJ, Dieffenbach P, Fredenburgh LE, Stearman RS, Geraci MW, Kourembanas S, and Christou H
- Subjects
- Acidosis chemically induced, Acidosis complications, Acidosis immunology, Animals, Cell Differentiation drug effects, Contractile Proteins biosynthesis, Contractile Proteins genetics, Drug Evaluation, Preclinical, Humans, Hypertension, Pulmonary enzymology, Hypertension, Pulmonary etiology, Hypertension, Pulmonary pathology, Hypoxia complications, Inflammation, Macrophages drug effects, Macrophages enzymology, Macrophages, Alveolar drug effects, Macrophages, Alveolar enzymology, Male, Muscle, Smooth, Vascular pathology, Myocytes, Smooth Muscle drug effects, Myocytes, Smooth Muscle enzymology, Protein Isoforms antagonists & inhibitors, Pulmonary Artery pathology, RNA, Messenger biosynthesis, RNA, Messenger genetics, Rats, Rats, Sprague-Dawley, Acetazolamide therapeutic use, Ammonium Chloride therapeutic use, Carbonic Anhydrase Inhibitors therapeutic use, Carbonic Anhydrases physiology, Hypertension, Pulmonary drug therapy
- Abstract
Inflammation and vascular smooth muscle cell (VSMC) phenotypic switching are causally linked to pulmonary arterial hypertension (PAH) pathogenesis. Carbonic anhydrase inhibition induces mild metabolic acidosis and exerts protective effects in hypoxic pulmonary hypertension. Carbonic anhydrases and metabolic acidosis are further known to modulate immune cell activation. To evaluate if carbonic anhydrase inhibition modulates macrophage activation, inflammation, and VSMC phenotypic switching in severe experimental pulmonary hypertension, pulmonary hypertension was assessed in Sugen 5416/hypoxia (SU/Hx) rats after treatment with acetazolamide or ammonium chloride (NH
4 Cl). We evaluated pulmonary and systemic inflammation and characterized the effect of carbonic anhydrase inhibition and metabolic acidosis in alveolar macrophages and bone marrow-derived macrophages (BMDMs). We further evaluated the treatment effects on VSMC phenotypic switching in pulmonary arteries and pulmonary artery smooth muscle cells (PASMCs) and corroborated some of our findings in lungs and pulmonary arteries of patients with PAH. Both patients with idiopathic PAH and SU/Hx rats had increased expression of lung inflammatory markers and signs of PASMC dedifferentiation in pulmonary arteries. Acetazolamide and NH4 Cl ameliorated SU/Hx-induced pulmonary hypertension and blunted pulmonary and systemic inflammation. Expression of carbonic anhydrase isoform 2 was increased in alveolar macrophages from SU/Hx animals, classically (M1) and alternatively (M2) activated BMDMs, and lungs of patients with PAH. Carbonic anhydrase inhibition and acidosis had distinct effects on M1 and M2 markers in BMDMs. Inflammatory cytokines drove PASMC dedifferentiation, and this was inhibited by acetazolamide and acidosis. The protective antiinflammatory effect of acetazolamide in pulmonary hypertension is mediated by a dual mechanism of macrophage carbonic anhydrase inhibition and systemic metabolic acidosis.- Published
- 2019
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38. Early caloric deprivation in preterm infants affects Bayley-III scales performance at 18-24 months of corrected age.
- Author
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Lithoxopoulou M, Rallis D, Christou H, Goutsiou E, Varaklioti A, Karagianni P, Tsakalidis C, Domeyer P, Kuriakeli G, and Soubasi V
- Subjects
- Bronchopulmonary Dysplasia diagnosis, Bronchopulmonary Dysplasia psychology, Cerebral Intraventricular Hemorrhage diagnosis, Cerebral Intraventricular Hemorrhage psychology, Developmental Disabilities psychology, Female, Follow-Up Studies, Gestational Age, Humans, Infant, Infant Nutrition Disorders psychology, Infant, Newborn, Infant, Premature, Diseases psychology, Prospective Studies, Risk Factors, Developmental Disabilities diagnosis, Energy Intake, Food Deprivation, Infant Nutrition Disorders diagnosis, Infant, Premature, Diseases diagnosis
- Abstract
Background: Adequate nutrition is essential for optimal neurodevelopment to preterm infants. Our aim was to evaluate the impact of caloric deprivation on Bayley-III scales performance at 18-24 months of corrected age, in a cohort of preterm infants., Methods: We prospectively enrolled infants with gestational age <30 weeks and birth weight <1500 g. Apart from a whole cohort analysis, we performed a subgroup analysis between infants received inadequate calories (<85 Kcal/kg/day) during the first two weeks of age, compared to a standard nutrition group. All infants underwent a Bayley-III assessment at 18-24 months of corrected age., Results: From the 63 preterm infants analysed, 25% had caloric deprivation compared to 75% with adequate nutrition. Caloric deprived infants were of lower gestational age and birth weight, and received a lower amount of enteral feeding during the first 14 days of age. There were no differences between the two groups regarding the common neonatal co-morbidities. Caloric deprived infants had significantly lower composite index scores at 18-24 months of corrected age. Caloric deprivation, late onset sepsis, necrotizing enterocolitis, and bronchopulmonary dysplasia were significant risk factors of neurodevelopmental impairment., Conclusions: Several neonatal factors affect the neurodevelopmental outcome of preterm infants, and nutrition may pose an important role., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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39. Macrophage FABP4 is required for neutrophil recruitment and bacterial clearance in Pseudomonas aeruginosa pneumonia.
- Author
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Liang X, Gupta K, Quintero JR, Cernadas M, Kobzik L, Christou H, Pier GB, Owen CA, and Çataltepe S
- Subjects
- Acute Lung Injury immunology, Animals, Bone Marrow immunology, Chemokine CXCL1 immunology, Inflammation immunology, Lung immunology, Mice, Mice, Inbred C57BL, Neutrophil Infiltration immunology, Pseudomonas Infections immunology, Fatty Acid-Binding Proteins immunology, Macrophages, Alveolar immunology, Neutrophils immunology, Pneumonia immunology, Pseudomonas aeruginosa immunology
- Abstract
Fatty acid binding protein 4 (FABP4), an intracellular lipid chaperone and adipokine, is expressed by lung macrophages, but the function of macrophage-FABP4 remains elusive. We investigated the role of FABP4 in host defense in a murine model of Pseudomonas aeruginosa pneumonia. Compared with wild-type (WT) mice, FABP4-deficient (FABP4
-/- ) mice exhibited decreased bacterial clearance and increased mortality when challenged intranasally with P. aeruginosa. These findings in FABP4-/- mice were associated with a delayed neutrophil recruitment into the lungs and were followed by greater acute lung injury and inflammation. Among leukocytes, only macrophages expressed FABP4 in WT mice with P. aeruginosa pneumonia. Chimeric FABP4-/- mice with WT bone marrow were protected from increased mortality seen in chimeric WT mice with FABP4-/- bone marrow during P. aeruginosa pneumonia, thus confirming the role of macrophages as the main source of protective FABP4 against that infection. There was less production of C-X-C motif chemokine ligand 1 (CXCL1) in FABP4-/- alveolar macrophages and lower airway CXCL1 levels in FABP4-/- mice. Delivering recombinant CXCL1 to the airways protected FABP4-/- mice from increased susceptibility to P. aeruginosa pneumonia. Thus, macrophage-FABP4 has a novel role in pulmonary host defense against P. aeruginosa infection by facilitating crosstalk between macrophages and neutrophils via regulation of macrophage CXCL1 production.-Liang, X., Gupta, K., Rojas Quintero, J., Cernadas, M., Kobzik, L., Christou, H., Pier, G. B., Owen, C. A., Çataltepe, S. Macrophage FABP4 is required for neutrophil recruitment and bacterial clearance in Pseudomonas aeruginosa pneumonia.- Published
- 2019
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40. Bronchopulmonary Dysplasia: An Update of Current Pharmacologic Therapies and New Approaches.
- Author
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Michael Z, Spyropoulos F, Ghanta S, and Christou H
- Abstract
Bronchopulmonary dysplasia (BPD) remains the most prevalent long-term morbidity of surviving extremely preterm infants and is associated with significant health care utilization in infancy and beyond. Recent advances in neonatal care have resulted in improved survival of extremely low birth weight (ELBW) infants; however, the incidence of BPD has not been substantially impacted by novel interventions in this vulnerable population. The multifactorial cause of BPD requires a multi-pronged approach for prevention and treatment. New approaches in assisted ventilation, optimal nutrition, and pharmacologic interventions are currently being evaluated. The focus of this review is the current state of the evidence for pharmacotherapy in BPD. Promising future approaches in need of further study will also be reviewed., Competing Interests: Declaration of conflicting interests:The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2018
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41. Impaired Pulmonary Arterial Vasoconstriction and Nitric Oxide-Mediated Relaxation Underlie Severe Pulmonary Hypertension in the Sugen-Hypoxia Rat Model.
- Author
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Christou H, Hudalla H, Michael Z, Filatava EJ, Li J, Zhu M, Possomato-Vieira JS, Dias-Junior C, Kourembanas S, and Khalil RA
- Subjects
- Animals, Cell Hypoxia, Cyclic GMP metabolism, Disease Models, Animal, Hemodynamics, Hypertension, Pulmonary metabolism, Male, Muscle, Smooth, Vascular pathology, Phenotype, Pulmonary Artery pathology, Rats, Rats, Sprague-Dawley, Signal Transduction, Vascular Remodeling, Hypertension, Pulmonary pathology, Hypertension, Pulmonary physiopathology, Nitric Oxide metabolism, Pulmonary Artery physiopathology, Vasodilation
- Abstract
Pulmonary vasoreactivity could determine the responsiveness to vasodilators and, in turn, the prognosis of pulmonary hypertension (PH). We hypothesized that pulmonary vasoreactivity is impaired, and we examined the underlying mechanisms in the Sugen-hypoxia rat model of severe PH. Male Sprague-Dawley rats were injected with Sugen (20 mg/kg s.c.) and exposed to hypoxia (9% O
2 ) for 3 weeks, followed by 4 weeks in normoxia (Su/Hx), or treated with Sugen alone (Su) or hypoxia alone (Hx) or neither (Nx). After hemodynamic measurements, the heart was assessed for right ventricular hypertrophy (Fulton's index); the pulmonary artery, aorta, and mesenteric arteries were isolated for vascular function studies; and contractile markers were measured in pulmonary arteries using quantitative polymerase chain reaction (PCR). Other rats were used for morphometric analysis of pulmonary vascular remodeling. Right ventricular systolic pressure and Fulton's index were higher in Su/Hx versus Su, Hx, and Nx rats. Pulmonary vascular remodeling was more prominent in Su/Hx versus Nx rats. In pulmonary artery rings, contraction to high KCl (96 mM) was less in Su/Hx versus Nx and Su, and phenylephrine-induced contraction was reduced in Su/Hx versus Nx, Hx, and Su. Acetylcholine (ACh)-induced relaxation was less in Su/Hx versus Nx and Hx, suggesting reduced endothelium-dependent vasodilation. ACh relaxation was inhibited by nitric oxide synthase (NOS) and guanylate cyclase blockade in all groups, suggesting a role of the NO-cGMP pathway. Nitrate/nitrite production in response to ACh was less in Su/Hx versus Nx, supporting reduced endothelial NO production. Sodium nitroprusside (10-8 M) caused less relaxation in Su/Hx versus Nx, Hx, and Su, suggesting a decreased responsiveness of vascular smooth muscle (VSM) to vasodilators. Neither contraction nor relaxation differed in the aorta or mesenteric arteries of all groups. PCR analysis showed decreased expression of contractile markers in pulmonary artery of Su/Hx versus Nx. The reduced responsiveness to vasoconstrictors and NO-mediated vasodilation in the pulmonary, but not systemic, vessels may be an underlying mechanism of severe PH in Su/Hx rats and appears to involve attenuation of the NO relaxation pathway and a switch of pulmonary VSM cells to a synthetic less reactive phenotype., (Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.)- Published
- 2018
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42. Adjuvant Effect of Bacille Calmette-Guérin on Hepatitis B Vaccine Immunogenicity in the Preterm and Term Newborn.
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Scheid A, Borriello F, Pietrasanta C, Christou H, Diray-Arce J, Pettengill MA, Joshi S, Li N, Bergelson I, Kollmann T, Dowling DJ, and Levy O
- Subjects
- Adult, Animals, Animals, Newborn, Cytokines genetics, Cytokines immunology, Female, Fetal Blood, Humans, Infant, Newborn, Infant, Premature, Leukocytes, Mononuclear immunology, Male, Mice, Inbred C57BL, Premature Birth, Term Birth, Young Adult, Adjuvants, Immunologic administration & dosage, BCG Vaccine administration & dosage, Hepatitis B Vaccines administration & dosage, Immunogenicity, Vaccine drug effects
- Abstract
Immunization is key to protecting term and preterm infants from a heightened risk of infection. However, preterm immunity is distinct from that of the term, limiting its ability to effectively respond to vaccines routinely given at birth, such as hepatitis B vaccine (HBV). As part of the Expanded Program on Immunization, HBV is often given together with the live-attenuated vaccine Bacille Calmette-Guérin (BCG), known to activate multiple pattern-recognition receptors. Of note, some clinical studies suggest BCG can enhance efficacy of other vaccines in term newborns. However, little is known about whether BCG can shape Th-polarizing cytokine responses to HBV nor the age-dependency of such effects, including whether they may extend to the preterm. To characterize the effects of BCG on HBV immunogenicity, we studied individual and combined administration of these vaccines to cord newborn and adult human whole blood and mononuclear cells in vitro and to neonatal and adult mice in vivo . Compared to either BCG or HBV alone, (BCG + HBV) synergistically enhanced in vitro whole blood production of IL-1β, while (BCG + HBV) also promoted production of several cytokines/chemokines in all age groups, age-specific enhancement included IL-12p70 in the preterm and GM-CSF in the preterm and term. In human mononuclear cells, (BCG + HBV) enhanced mRNA expression of several genes including CSF2 , which contributed to clustering of genes by vaccine treatment via principle component analysis. To assess the impact of BCG on HBV immunization, mice of three different age groups were immunized subcutaneously with, BCG, HBV, (BCG + HBV) into the same site; or BCG and HBV injected into separate sites. Whether injected into a separate site or at the same site, co-administration of BCG with HBV significantly enhanced anti-HBV IgG titers in mice immunized on day of life-0 or -7, respectively, but not in adult mice. In summary, our data demonstrate that innate and adaptive vaccine responses of preterm and term newborns are immunologically distinct. Furthermore, BCG or "BCG-like" adjuvants should be further studied as a promising adjuvantation approach to enhance immunogenicity of vaccines to protect these vulnerable populations.
- Published
- 2018
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43. Is There More to Zika? Complex Cardiac Disease in a Case of Congenital Zika Syndrome.
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Angelidou A, Michael Z, Hotz A, Friedman K, Emani S, LaRovere K, and Christou H
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- Adult, Brain diagnostic imaging, Female, Heart Diseases etiology, Hospice Care, Humans, Infant, Newborn, Magnetic Resonance Imaging, Male, Microcephaly diagnostic imaging, Microcephaly etiology, Nervous System Malformations diagnostic imaging, Pregnancy, Ultrasonography, Prenatal, Zika Virus pathogenicity, Zika Virus Infection congenital, Brain pathology, Microcephaly virology, Nervous System Malformations virology, Pregnancy Complications, Infectious virology, Zika Virus Infection complications
- Abstract
The epidemic of Zika virus (ZIKV) has resulted in a surge of newborns with microcephaly and brain abnormalities. In this report, we describe the first case, to our knowledge, of congenital Zika syndrome with concomitant critical congenital heart disease. The mother had a confirmed ZIKV infection in the first trimester of pregnancy. Fetal ultrasonography at 31 weeks of gestation revealed cerebral cortical calcifications and hypoplastic left heart syndrome. The severity of brain involvement was assessed by postnatal magnetic resonance imaging and echocardiogram, and palliative surgery was performed. The ethical dimensions of this infant's clinical management are discussed. ZIKV is known to affect neural progenitor cells, but whether it could have a tropism for other tissues remains unclear., (© 2017 S. Karger AG, Basel.)
- Published
- 2018
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44. Cord Blood Adipocyte Fatty Acid-Binding Protein Levels Correlate With Gestational Age and Birth Weight in Neonates.
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Joung KE, Cataltepe SU, Michael Z, Christou H, and Mantzoros CS
- Subjects
- Adult, Cross-Sectional Studies, Enzyme-Linked Immunosorbent Assay, Female, Fetal Blood, Humans, Infant, Extremely Premature blood, Infant, Newborn, Male, Birth Weight, Fatty Acid-Binding Proteins blood, Fetal Macrosomia blood, Gestational Age, Infant, Premature blood, Infant, Small for Gestational Age blood
- Abstract
Context: Infants born small for gestational age (SGA) have increased risk for obesity and metabolic syndrome, but the underlying mechanisms are not fully elucidated. Adipocyte fatty acid-binding protein (AFABP) is an adipokine that has been implicated in modulation of insulin sensitivity and lipid metabolism. Higher plasma AFABP levels are associated with increased risk of metabolic syndrome and cardiovascular morbidity in adults. Alterations in AFABP levels during fetal growth have not been characterized., Objective: To examine AFABP levels in neonatal cord blood in relation to gestational age and birth weight., Design: A cross-sectional study of 361 neonates born at a tertiary academic center., Outcome Measures: Plasma AFABP levels were measured by enzyme-linked immunosorbent assay. For comparison, venous samples from 26 adults were analyzed., Results: AFABP levels were higher in neonates compared with adults (P < 0.01). Preterm infants had higher AFABP levels [48.2 (31.2 to 73.3) ng/mL] compared with full-term infants [35.8 (25.1 to 51.5)] ng/mL, P < 0.01). There was a negative correlation between AFABP and gestational age (r = 0.28, P = 0.02). Among full-term infants, AFABP levels in SGA infants were lower [28.6 (24.2 to 37.3) ng/mL], compared with appropriate for gestational age [36.1 (25.5 to 50.4) ng/mL] and large for gestational age infants [45.0 (24.6 to 62.4) ng/mL, P < 0.05]., Conclusions: These associations may reflect the higher metabolic activity during fetal development. AFABP may also be involved in fetal growth and the association between SGA status and obesity and metabolic syndrome in later life., (Copyright © 2017 by the Endocrine Society)
- Published
- 2017
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45. Establishing Effective Mentoring Networks: Rationale and Strategies.
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Christou H, Dookeran N, Haas A, Di Frances C, Emans SJ, Milstein ME, Kram KE, and Seely EW
- Abstract
Introduction: Mentoring networks constitute an effective mentoring model in academic medicine and significantly add to the traditional dyadic mentor-mentee relationship. There is an unmet educational need for medical faculty to recognize the importance and characteristics of effective mentoring networks and to develop tools and strategies to appraise and construct strong, individualized mentoring networks., Methods: An interactive educational session on developmental mentoring networks for physicians and scientists in an academic environment was designed. This session can be presented as part of a series on mentoring topics or as a stand-alone module., Results: Using preassigned readings and a mentoring network mapping exercise, participants were able to describe their current mentoring relationships and identify strengths and opportunities for enhancing their effectiveness., Conclusion: A structured educational session is a useful approach towards advancing the ability of academic mentors to help create optimally effective mentoring networks. The learning environment is enhanced by the interactive nature of the session when used in an interdisciplinary cohort of faculty participants., Competing Interests: None to report.
- Published
- 2017
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46. Sustaining careers of physician-scientists in neonatology and pediatric critical care medicine: formulating supportive departmental policies.
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Christou H, Dizon ML, Farrow KN, Jadcherla SR, Leeman KT, Maheshwari A, Rubin LP, Stansfield BK, and Rowitch DH
- Subjects
- Academic Medical Centers organization & administration, Career Choice, Focus Groups, Guidelines as Topic, Hospitals, Pediatric organization & administration, Humans, Job Satisfaction, Medical Staff, Hospital, Mentors, Program Development, Surveys and Questionnaires, Workforce, Critical Care organization & administration, Neonatology organization & administration, Pediatrics organization & administration, Physicians, Translational Research, Biomedical organization & administration
- Abstract
Understanding mechanisms of childhood disease and development of rational therapeutics are fundamental to progress in pediatric intensive care specialties. However, Division Chiefs and Department Chairs face unique challenges when building effective laboratory-based research programs in Neonatal and Pediatric Intensive Care, owing to high clinical demands necessary to maintain competence as well as financial pressures arising from fund flow models and the current extramural funding climate. Given these factors, the role of institutional support that could facilitate successful transition of promising junior faculty to independent research careers is ever more important. Would standardized guidelines of such support provide greater consistency among institutions? We addressed preliminary questions during a national focus group, a workshop and a survey of junior and senior academicians to solicit recommendations for optimal levels of protected time and resources when starting an independent laboratory. The consensus was that junior faculty should be assigned no more than 8 wk clinical service and should obtain start-up funds of $500K-1M exclusive of a 5-y committed salary support. Senior respondents placed a higher premium on protected time than junior faculty.
- Published
- 2016
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47. Cord blood irisin levels are positively correlated with birth weight in newborn infants.
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Joung KE, Park KH, Filippaios A, Dincer F, Christou H, and Mantzoros CS
- Subjects
- Adult, Female, Humans, Infant, Newborn, Insulin blood, Male, Biomarkers blood, Birth Weight, Fetal Blood metabolism, Fetal Development, Fibronectins blood
- Abstract
Background: Irisin is a novel myokine, secreted from skeletal muscle after exercise. Irisin mediates exercise-related energy expenditure by turning white adipose tissue (WAT) into brown adipose tissue (BAT). Thus, irisin is considered as a potential biomarker for obesity and metabolic syndrome. Infants born small for gestational age (SGA) have increased risk for metabolic syndrome. However, the physiologic role of irisin in neonates remains to be studied., Objective: To evaluate the association of umbilical cord blood irisin levels with gestational age and birth weight categories in neonates., Methods: A cross-sectional study of 341 newborns, from 26 to 41weeks' gestation. We collected umbilical cord blood and analyzed plasma for irisin by ELISA., Results: Plasma irisin levels were positively correlated with gestational age (r=0.21, p<0.001), and birth weight Z-score (r=0.18, p<0.001). SGA infants had significantly lower irisin (median [interquartile range] 55.38 [46.56-65.72]ng/mL) compared to appropriate for gestational age infants (64.41 [53.87-76.76]ng/mL) and large for gestational age infants (68.70 [54.78-79.09]ng/mL, p<0.01). The association between SGA and lower irisin remained significant in multivariate analysis independent of gestational age, maternal age, maternal BMI, and gestational diabetes (p=0.03). In singleton infants, irisin was also significantly negatively associated with maternal preeclampsia (p=0.01)., Conclusions: Our results support the notion that irisin may have a physiologic role in neonates. We speculate that decreased levels of irisin in SGA infants may contribute to the development of catch-up growth and metabolic syndrome later in life., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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48. Elk-3 is a KLF4-regulated gene that modulates the phagocytosis of bacteria by macrophages.
- Author
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Tsoyi K, Geldart AM, Christou H, Liu X, Chung SW, and Perrella MA
- Subjects
- Animals, Blotting, Western, Cell Line, Chromatin Immunoprecipitation, Escherichia coli Infections immunology, Heme Oxygenase-1 immunology, Inflammation immunology, Kruppel-Like Factor 4, Kruppel-Like Transcription Factors genetics, Membrane Proteins immunology, Mice, Mice, Knockout, Mutagenesis, Site-Directed, Phagocytosis genetics, Proto-Oncogene Proteins c-ets genetics, Real-Time Polymerase Chain Reaction, Transfection, Gene Expression Regulation immunology, Kruppel-Like Transcription Factors immunology, Macrophages immunology, Phagocytosis immunology, Proto-Oncogene Proteins c-ets immunology
- Abstract
ETS family proteins play a role in immune responses. A unique member of this family, Elk-3, is a transcriptional repressor that regulates the expression of HO-1. Elk-3 is very sensitive to the effects of inflammatory mediators and is down-regulated by bacterial endotoxin (LPS). In the present study, exposure of mouse macrophages to Escherichia coli LPS resulted in decreased, full-length, and splice-variant isoforms of Elk-3. We isolated the Elk-3 promoter and demonstrated that LPS also decreased promoter activity. The Elk-3 promoter contains GC-rich regions that are putative binding sites for zinc-finger transcription factors, such as Sp1 and KLFs. Mutation of the GC-rich region from bp -613 to -603 blunted LPS-induced down-regulation of the Elk-3 promoter. Similar to the LPS response, coexpression of KLF4 led to repression of Elk-3 promoter activity, whereas coexpression of Sp1 increased activity. ChIP assays revealed that KLF4 binding to the Elk-3 promoter was increased by LPS exposure, and Sp1 binding was decreased. Thus, down-regulation of Elk-3 by bacterial LPS is regulated, in part, by the transcriptional repressor KLF4. Overexpression of Elk-3, in the presence of E. coli bacteria, resulted in decreased macrophage phagocytosis. To determine whether limited expression of HO-1 may contribute to this response, we exposed HO-1-deficient bone marrow-derived macrophages to E. coli and found a comparable reduction in bacterial phagocytosis. These data suggest that down-regulation of Elk-3 and the subsequent induction of HO-1 are important for macrophage function during the inflammatory response to infection., (© Society for Leukocyte Biology.)
- Published
- 2015
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49. Cord blood levels of osteopontin as a phenotype marker of gestational age and neonatal morbidities.
- Author
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Joung KE, Christou H, Park KH, and Mantzoros CS
- Subjects
- Adult, Biomarkers blood, Birth Weight, Cross-Sectional Studies, Female, Humans, Infant, Newborn, Infant, Premature blood, Logistic Models, Male, Middle Aged, Phenotype, Placenta, Pregnancy, Risk Factors, Vitamin D analogs & derivatives, Vitamin D blood, Fetal Blood chemistry, Gestational Age, Metabolic Syndrome epidemiology, Osteopontin blood
- Abstract
Objectives: Osteopontin (OPN) is a proinflammatory cytokine associated with metabolic syndrome. Extreme birth weight categories including small for gestational age (SGA), and large for gestational age (LGA) are risk factors for metabolic syndrome. However normal levels of plasma OPN in neonates and the relationship of OPN to fetal growth remain unknown. We evaluated the association of umbilical cord blood OPN with gestational age, birth weight, and neonatal outcomes., Methods: A cross-sectional study of 261 newborns of all gestational ages beginning at week 26, and 26 adults for comparison was performed. Umbilical cord blood from newborns and analyzed plasma for OPN by ELISA was collected., Results: Plasma OPN was significantly higher in neonates (414.65 ± 136.72 ng/mL) compared to adults (33.37 ± 14.66 ng/mL, P < 0.001). There was an inverse correlation between OPN and gestational age (r = -0.48, P < 0.0001). LGA infants had lower OPN than appropriate for gestational age (AGA) infants, but LGA was not an independent predictor of OPN in multivariate analysis. Among preterm infants, patent ductus arteriosus (PDA) was independently associated with higher OPN (OR = 2.49, P = 0.02)., Conclusion: Our results raise the possibility that OPN has a physiologic role in fetal growth and development, and may be a useful biomarker for PDA., (Copyright © 2013 The Obesity Society.)
- Published
- 2014
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50. Vitamin D status among preterm and full-term infants at birth.
- Author
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Burris HH, Van Marter LJ, McElrath TF, Tabatabai P, Litonjua AA, Weiss ST, and Christou H
- Subjects
- Fetal Blood metabolism, Humans, Infant, Newborn, Infant, Premature, Vitamin D blood
- Abstract
Background: Risk factors for maternal vitamin D deficiency and preterm birth overlap, but the distribution of 25-hydroxyvitamin D (25(OH)D) levels among preterm infants is not known. We aimed to determine the associations between 25(OH)D levels and gestational age., Methods: We measured umbilical cord plasma levels of 25(OH)D from 471 infants born at Brigham and Women's Hospital in Boston. We used generalized estimating equations to determine whether preterm (<37 wks' gestation) or very preterm (<32 wks' gestation) infants had greater odds of having 25(OH)D levels below 20 ng/ml than more mature infants. We adjusted for potential confounding by season of birth, maternal age, race, marital status, and singleton or multiple gestation., Results: Mean cord plasma 25(OH)D level was 34.0 ng/ml (range: 4.1-95.3 and SD: 14.1). Infants born before 32 wks' gestation had increased odds of having 25(OH)D levels below 20 ng/ml in unadjusted (odds ratio (OR): 2.2; 95% confidence interval (CI): 1.1-4.3) and adjusted models (OR: 2.4; 95% CI: 1.2-5.3) as compared with more mature infants., Conclusion: Infants born in <32 wks' gestation are at higher risk than more mature infants for low 25(OH)D levels. Further investigation of the relationships between low 25(OH)D levels and preterm birth and its sequelae is thus warranted.
- Published
- 2014
- Full Text
- View/download PDF
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