Intravitreal Aflibercept vs Laser Therapy for Retinopathy of Prematurity: Two-Year Efficacy and Safety Outcomes in the Nonrandomized Controlled Trial FIREFLEYE next.

Importance: Prospective long-term data after retinopathy of prematurity (ROP) treatment with anti-vascular endothelial growth factor injections vs laser therapy are scarce. The FIREFLEYE (Aflibercept for ROP IVT Injection vs Laser Therapy) next trial is prospectively evaluating the long-term efficacy and safety outcomes following ROP treatment with intravitreal aflibercept vs laser therapy. Objective: To evaluate 2-year ophthalmic and safety outcomes after 0.4-mg aflibercept injection or laser therapy in the 24-week randomized (2:1) FIREFLEYE trial (FIREFLEYE outcomes previously reported). Design, Setting, and Participants: This prospective nonrandomized controlled trial performed in 24 countries in Asia, Europe, and South America (2020-2025) follows up participants treated in the FIREFLEYE randomized clinical trial (2019-2021) through 5 years of age. Participants included children born very or extremely preterm (gestational age ≤32 weeks) or with very or extremely low birth weight (≤1500 g) who were previously treated with a 0.4-mg injection of aflibercept compared with laser therapy for severe acute-phase ROP. Data for the present interim analysis were acquired from March 18, 2020, to July 25, 2022. Interventions: Complications of ROP treated at investigator discretion (no study treatment). Main Outcomes and Measures: Efficacy end points included ROP status, unfavorable structural outcomes, ROP recurrence, treatment for ROP complications, completion of vascularization, and visual function. Safety end points included adverse events and growth and neurodevelopmental outcomes. Results: Overall, 100 children were enrolled (median gestational age, 26 [range, 23-31] weeks; 53 boys and 47 girls). Of these, 21 were Asian, 2 were Black, 75 were White, and 2 were of more than 1 race. At 2 years of age, 61 of 63 children (96.8%) in the aflibercept group vs 30 of 32 (93.8%) in the laser group had no ROP. Through 2 years of age, 62 of 66 (93.9%) in the aflibercept group and 32 of 34 (94.1%) in the laser group had no unfavorable structural outcomes. No new retinal detachment occurred during the study. Four children in the aflibercept group (6.1%) were treated for ROP complications before 1 year of age (2 had preexisting end-stage disease and total retinal detachment; 1 had reactivated plus disease; and 1 had recurrent retinal neovascularization not further specified). Most children were able to fix and follow a 5-cm toy (aflibercept group, 118 of 122 eyes [96.7%] among 63 children; laser group, 62 of 63 eyes [98.4%] among 33 children). High myopia was present in 9 of 115 eyes (7.8%) among 5 children in the aflibercept group and 13 of 60 eyes (21.7%) among 9 children in the laser group. No relevant differences in growth and neurodevelopmental outcomes by Bayley Scales of Infant and Toddler Development, Third Edition and Vineland Adaptive Behavior Scales, Second Edition were identified. Conclusions and Relevance: In this nonrandomized follow-up of a randomized clinical trial comparing treatment of severe acute-phase ROP with 0.4-mg injection of aflibercept and laser, disease control was stable and visual function was appropriate in children through 2 years of age. No adverse effects on safety, including growth and neurodevelopment, were identified. These findings provide clinically relevant long-term information on intravitreal aflibercept injection therapy for ROP. Trial Registration: ClinicalTrials.gov Identifier: NCT04015180.

Inhaled nitric oxide therapy for preterm infants after 7 days of age: a scoping review protocol.

INTRODUCTION: Inhaled nitric oxide (iNO) use is recommended for persistent pulmonary hypertension of the newborn in term and late preterm infants. Recently, iNO therapy to prevent bronchopulmonary dysplasia (BPD) or rescue for hypoxic respiratory failure and pulmonary hypertension secondary to BPD has increasingly been used in preterm infants after 7 days of postnatal age (in the postacute phase), despite its off-label use. However, the initiation criteria of iNO therapy for preterm infants in the postacute phase are varied. The aim of this scoping review is to identify the clinical and/or echo findings at the initiation of iNO therapy in preterm infants in the postacute phase. METHODS AND ANALYSIS: We will search PubMed, Embase and the Japanese database 'Ichushi.' The following studies will be included in the review: randomised controlled trials, prospective/retrospective cohort studies, case-control studies and case series on iNO therapy for preterm infants in the postacute phase; studies published between January 2003 and August 2023; studies conducted in developed countries and studies written in English or Japanese. We will independently screen, extract and chart data using the population-concept-context framework following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. We will summarise the characteristics and findings of the included studies. ETHICS AND DISSEMINATION: Obtaining an institutional review board approval is not required because of the nature of this review. A final report of review findings will be published and disseminated through a peer-reviewed journal and presentation at relevant conferences. TRIAL REGISTRATION NUMBER: UMIN000051498.

Systemic exposure to aflibercept after intravitreal injection in premature neonates with retinopathy of prematurity: results from the FIREFLEYE randomized phase 3 study.

BACKGROUND: There are no data on pharmacokinetics, pharmacodynamics, and immunogenicity of intravitreal aflibercept in preterm infants with retinopathy of prematurity (ROP). FIREFLEYE compared aflibercept 0.4 mg/eye and laser photocoagulation in infants with acute-phase ROP requiring treatment. METHODS: Infants (gestational age ≤32 weeks or birthweight ≤1500 g) with treatment-requiring ROP in ≥1 eye were randomized 2:1 to receive aflibercept 0.4 mg or laser photocoagulation at baseline in this 24-week, randomized, open-label, noninferiority, phase 3 study. Endpoints include concentrations of free and adjusted bound aflibercept in plasma, pharmacokinetic/pharmacodynamic exploration of systemic anti-vascular endothelial growth factor effects, and immunogenicity. RESULTS: Of 113 treated infants, 75 received aflibercept 0.4 mg per eye at baseline (mean chronological age: 10.4 weeks), mostly bilaterally (71 infants), and with 1 injection/eye (120/146 eyes). Concentrations of free aflibercept were highly variable, with maximum concentration at day 1, declining thereafter. Plasma concentrations of adjusted bound (pharmacologically inactive) aflibercept increased from day 1 to week 4, decreasing up to week 24. Six infants experienced treatment-emergent serious adverse events within 30 days of treatment; aflibercept concentrations were within the range observed in other infants. There was no pattern between free and adjusted bound aflibercept concentrations and blood pressure changes up to week 4. A low-titer (1:30), non-neutralizing, treatment-emergent anti-drug antibody response was reported in 1 infant, though was not clinically relevant. CONCLUSIONS: 24-week data suggest intravitreal aflibercept for treatment of acute-phase ROP is not associated with clinically relevant effects on blood pressure, further systemic adverse events, or immunogenicity. GOV IDENTIFIER: NCT04004208.

Evaluation of Postnatal Complications in Clinical and Histological Chorioamnionitis in Extremely Preterm Infants: A Japanese Cohort Study.

OBJECTIVE: Terminating pregnancy appropriately before the intrauterine infection has progressed may have an improved prognosis for preterm infants. We evaluate how the combination of histological chorioamnionitis (hCAM) and clinical chorioamnionitis (cCAM) affects the short-term prognosis of infants. STUDY DESIGN: This retrospective multicenter cohort study based on the Neonatal Research Network of Japan included extremely preterm infants born weighing <1,500 g between 2008 and 2018. Demographic characteristics, morbidity, and mortality were compared between the cCAM(-)hCAM(+) and cCAM(+)hCAM(+) groups. RESULTS: We included 16,304 infants. The progression to cCAM in infants with hCAM was correlated with the increase in home oxygen therapy (HOT) (adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.11-1.44) and persistent pulmonary hypertension of the newborn (PPHN) (1.20, 1.04-1.38). Furthermore, increased progression of the hCAM stage in infants with cCAM correlated with an increase in bronchopulmonary dysplasia (BPD; 1.05, 1.01-1.11), HOT (1.10, 1.02-1.18), and PPHN (1.09, 1.01-1.18). However, it had a negative impact on hemodynamically significant patent ductus arteriosus (hsPDA; 0.87, 0.83-0.92) and death before discharge from the neonatal intensive care unit (NICU; 0.88, 0.81-0.96). CONCLUSION: Progression to cCAM in infants with hCAM positively correlated with HOT and PPHN. Progression of hCAM staging in infants with cCAM further increases the prevalence of BPD and the need for HOT and PPHN while reducing the prevalence of hsPDA and death before discharge from the NICU. The effects of the progressive hCAM stage in infants with cCAM vary from positive to negative by disease. KEY POINTS: · Retrospective multicenter cohort study based on the Neonatal Research Network of Japan.. · Clinical and histological chorioamnionitis increases the prevalence of BPD, HOT, and PPHN.. · Progression of histological chorioamnionitis in infants reduces the prevalence of hsPDA and death..

Bronchopulmonary Dysplasia in Extremely Premature Infants: A Scoping Review for Identifying Risk Factors.

BACKGROUND: Over the years, bronchopulmonary dysplasia (BPD) affects the pulmonary function of infants, resulting in chronic health burdens for infants and their families. The aim of this scoping review was to screen available evidence regarding perinatal risk factors associated with the development and severity of BPD. METHODS: The eligibility criteria of the studies were year of publication between 2016 and 2021; setting of a developed country; English or Japanese as the study language; and randomized controlled, cohort, or case-control design. The titles and abstracts of the studies were screened by independent reviewers. RESULTS: Of 8189 eligible studies, 3 were included for severe BPD and 26 were included for moderate BPD. The risk factors for severe BPD were male sex, iatrogenic preterm birth, maternal hypertensive disorders of pregnancy (HDP), low gestational age, small-for-gestational-age (SGA) birth weight, mechanical ventilation on day 1, and need for patent ductus arteriosus (PDA) management. The risk factors for moderate or severe BPD included male sex, premature rupture of membranes, clinical chorioamnionitis, maternal HDP, SGA birth weight, bubbly/cystic appearance on X-ray, and PDA management. CONCLUSIONS: We identified several risk factors for BPD. We plan to confirm the validity of the new classification using the existing dataset.

Inhaled Nitric Oxide Therapy in the Post-Acute Phase in Extremely Preterm Infants: A Japanese Cohort Study.

OBJECTIVE: To determine the trends in inhaled nitric oxide (iNO) utilization in the late phase of hospitalization in a large Japanese cohort of extremely preterm infants and evaluate its benefit on long-term outcomes. STUDY DESIGN: This was a retrospective multicenter cohort study of 15 977 extremely preterm infants born at <28 weeks of gestational age between 2003 and 2016, in the Neonatal Research Network, Japan. Demographic characteristics, morbidity, and mortality were compared between extremely preterm infants with and without post-acute iNO therapy. Multivariable logistic analysis was performed to determine factors associated with post-acute iNO and its impact on neurodevelopmental outcomes at 3 years of age. RESULTS: Post-acute iNO utilization rates increased from 0.3% in 2009 to 1.9% in 2016, even under strict insurance coverage rules starting in 2009. Gestational age (1-week increment; aOR 0.82, 95% CI 0.76-0.88), small for gestational age (1.47, 1.08-1.99), histologic chorioamnionitis (1.50, 1.21-1.86), 5-minute Apgar score <4 (1.51, 1.10-2.07), air leak (1.92, 1.30-2.83), and bubbly/cystic appearance on chest X-Ray (1.68, 1.37-2.06) were associated with post-acute iNO. Post-acute iNO was not associated with neurodevelopmental outcomes at 3 years of age. CONCLUSIONS: The increasing post-acute iNO utilization rate among extremely preterm infants has been concurrent with improved survival rates of extremely preterm infants in Japan. Infants treated with post-acute iNO had more severe disease and complications than the comparison group, but there were no differences in neurodevelopmental outcome at 3 years. This suggests post-acute iNO may benefit extremely preterm infants.

Small for Gestational Age Affects Outcomes on Singletons and Inborn Births in Extremely Preterm Infants: A Japanese Cohort Study.

OBJECTIVE: This study aimed to compare the short- and long-term outcomes of extremely preterm small for gestational age (SGA) infants and appropriate for gestational age (AGA) infants in Japan. STUDY DESIGN: We retrospectively assessed 434 SGA and 1,716 AGA infants born at 22 to 27 weeks of gestational age (GA) and examined their outcomes on singletons and inborn births between 2003 and 2012. Infants were followed-up for 3 years, and the clinical characteristics and outcomes were compared. Fisher's exact and Student's t-tests were used for independent sample comparison. Logistic regression was used to identify associated factors. RESULTS: The prevalence of intraventricular hemorrhage ≥ grade 3 was significantly lower (adjusted odds ratio [aOR]: 0.28; 95% confidence interval [CI]: 0.11 - 0.72), and the prevalence of bronchopulmonary dysplasia at 36 weeks of GA and the need for home oxygen therapy were significantly higher (aOR: 2.20; 95% CI: 1.66 - 2.91 and aOR: 2.46; 95% CI: 1.75-3.47, respectively) in SGA infants than in AGA infants. SGA infants born at 24 to 25 weeks of GA had a significantly higher prevalence of developmental quotient (DQ) < 70 (aOR: 1.73; 95% CI: 1.08 - 2.77). Those born at 26 to 27 weeks of GA showed a significantly higher prevalence of cerebral palsy (CP) and visual impairment (aOR: 2.31; 95% CI: 1.22 - 4.40 and aOR: 2.61; 95% CI: 1.21 - 5.61, respectively). CONCLUSION: In SGA infants, birth at 24 to 25 weeks of GA is an independent risk factor for DQ < 70, and birth at 26 to 27 weeks of GA is an independent risk factor for CP and visual impairment. However, we did not consider nutritional and developmental factors, and a longer follow-up would help assess neurodevelopmental outcomes. KEY POINTS: · SGA is a risk factor for poor outcomes.. · In SGA infants, birth at 25 to 26 weeks is a risk factor for low a DQ.. · In SGA infants, birth at 26 to 27 weeks is a risk factor for CP..

Effect of Intravitreal Aflibercept vs Laser Photocoagulation on Treatment Success of Retinopathy of Prematurity: The FIREFLEYE Randomized Clinical Trial.

Importance: Laser photocoagulation, which is the standard treatment for retinopathy of prematurity (ROP), can have adverse events. Studies of anti-vascular endothelial growth factor injections have suggested efficacy in the treatment of ROP, but few studies have directly compared them with laser treatments. Objective: To compare intravitreal aflibercept vs laser photocoagulation in infants with ROP requiring treatment. Design, Setting, and Participants: This noninferiority, phase 3, 24-week, randomized clinical trial was conducted in 27 countries (64 hospital sites) throughout Asia, Europe, and South America. Overall, 118 infants (gestational age ≤32 weeks at birth or birth weight ≤1500 g) with ROP severity (zone I stage 1+ [stage 1 plus increased disease activity], zone I stage 2+, zone I stage 3, zone I stage 3+, zone II stage 2+, or zone II stage 3+) requiring treatment or with aggressive posterior ROP in at least 1 eye were enrolled between September 25, 2019, and August 28, 2020 (the last visit occurred on February 12, 2021). Interventions: Infants were randomized 2:1 to receive a 0.4-mg dose of intravitreal aflibercept (n = 75) or laser photocoagulation (n = 43) at baseline. Additional treatment was allowed as prespecified. Main Outcomes and Measures: The primary outcome was the proportion of infants without active ROP and unfavorable structural outcomes 24 weeks after starting treatment (assessed by investigators). The requirement for rescue treatment was considered treatment failure. Intravitreal aflibercept was deemed noninferior if the lower limit of the 1-sided 95% bayesian credible interval for the treatment difference was greater than -5%. Results: Among 118 infants randomized, 113 were treated (mean gestational age, 26.3 [SD, 1.9] weeks; 53 [46.9%] were female; 16.8% had aggressive posterior ROP, 19.5% had zone I ROP, and 63.7% had zone II ROP) and 104 completed the study. Treatment (intravitreal aflibercept: n = 75; laser photocoagulation: n = 38) was mostly bilateral (92.9%), and 82.2% of eyes in the intravitreal aflibercept group received 1 injection per eye. Treatment success was 85.5% with intravitreal aflibercept vs 82.1% with laser photocoagulation (between-group difference, 3.4% [1-sided 95% credible interval, -8.0% to ∞]). Rescue treatment was required in 4.8% (95% CI, 1.9% to 9.6%) of eyes in the intravitreal aflibercept group vs 11.1% (95% CI, 4.9% to 20.7%) of eyes in the laser photocoagulation group. The serious adverse event rates were 13.3% (ocular) and 24.0% (systemic) in the intravitreal aflibercept group compared with 7.9% and 36.8%, respectively, in the laser photocoagulation group. Three deaths, which occurred 4 to 9 weeks after intravitreal aflibercept treatment, were considered unrelated to aflibercept by the investigators. Conclusions and Relevance: Among infants with ROP, intravitreal aflibercept compared with laser photocoagulation did not meet criteria for noninferiority with respect to the primary outcome of the proportion of infants achieving treatment success at week 24. Further data would be required for more definitive conclusions regarding the comparative effects of intravitreal aflibercept and laser photocoagulation in this population. Trial Registration: ClinicalTrials.gov Identifier: NCT04004208.

Severe bronchopulmonary dysplasia in extremely premature infants: a scoping review protocol for identifying risk factors.

INTRODUCTION: The remarkable improvement in the long-term prognosis of extremely premature infants has led to an increase in the number of cases of bronchopulmonary dysplasia (BPD). BPD affects pulmonary function and developmental outcomes, resulting in high chronic health burdens for infants and their families over the years. Therefore, identifying its risk factors in the early period of life and exploring better prophylactics and treatment strategies are important.The objectives of our scoping review are to screen available evidence, identify perinatal risk factors involved in the development and severity of BPD and devise a novel disease classification system that can predict long-term prognosis. METHODS AND ANALYSIS: Eligibility criteria are as follows: articles published from 2002 to 2021; studies conducted in developed countries; articles written in English (PubMed) or Japanese (Ichushi); randomised controlled trials, prospective/retrospective cohort studies or case-control studies; extremely premature infants born before 28 weeks of gestational age; and articles in which endpoint was severe BPD as classified by the National Institute of Child Health and Human Development.We will screen the titles and abstracts of studies identified by independent reviewers using the population-concept-context framework. After a full-text review and data charting, we will provide the perinatal risk factors for severe BPD along with the risk ratio or odds ratio, 95% confidence interval and p values. ETHICS AND DISSEMINATION: Institutional review board approval is not required due to the nature of the study. The results of this review will be disseminated through peer-reviewed publications and presentations at relevant conferences.Protocol V.1, 22 September 2021 TRIAL REGISTRATION NUMBER: UMIN000045529.

Evaluation of postoperative complications for patent ductus arteriosus in extremely-low-birthweight infants.

BACKGROUND: Patent ductus arteriosus (PDA), which disrupts the hemodynamics early after birth, causes intraventricular hemorrhage and neonatal necrotizing. Unlike medical treatment for hemodynamically significant PDA, there are institutional disparities in the criteria for surgical treatment METHODS: We aimed to clarify the postoperative indications of surgery for hemodynamically significant PDA and the postoperative complications associated with surgery. RESULTS: Thirty-six extremely-low-birthweight infants (median gestational age 25.2 weeks, median birthweight 699 g) required video-assisted thoracoscopic surgery for PDA (VATS-PDA). The treatment indication of VATS-PDA was resistance to medical treatment in 17 cases, relapsed PDA in 15 cases, and no additional administration of indomethacin because of severe side effects in four cases. Complications with VATS-PDA occurred in eight of 36 cases. There were three cases of pneumothorax, two of thoracotomy transition, two of pulmonary hemorrhage, and four of post-ligation cardiac syndrome (PLCS). VATS-PDA-related death occurred in two cases due to PLCS. The frequency of four or more administrations of indomethacin, with or without postoperative complications, was 88% vs. 39%, respectively (P = 0.04). CONCLUSIONS: All postoperative deaths were caused by PLCS, which had the highest risk of poor prognosis. VATS-PDA should be considered for unclosed PDA after one course of indomethacin administration.

Morphological characterization of pulmonary microvascular disease in bronchopulmonary dysplasia caused by hyperoxia in newborn mice.

PURPOSE: Pulmonary microvascular injury is associated with the pathogenesis of bronchopulmonary dysplasia (BPD). To characterize the mechanisms of pulmonary vascular disease resulting from BPD, we studied the ultrastructural changes affecting pulmonary microvasculature. METHODS: Newborn ICR mice were exposed to 85% hyperoxia or normoxia for 14 days, and then normal air replacement conditions for the following 7 days. At postnatal day (P)14 and P21, lungs were harvested for ultrastructural examination and assessment of pulmonary hypertension. RESULTS: The ultrastructure of pulmonary microvasculature in the hyperoxia-exposed lungs revealed a collapsed capillary lumen. This was due to the abnormal morphology of endothelial cells (ECs) characterized by heterogeneously thick cytoplasm. Compared to normal air controls, the specimens displayed also remarkably thick blood-air barriers (BABs), most of which were occupied by EC layer components. Structural changes were accompanied by increased pulmonary artery medial thickness and right ventricular hypertrophy (RVH). Moreover, abnormalities in ECs persisted even after exposure to 7 days of normal air replacement conditions. Results were confirmed by morphometric quantification. CONCLUSION: Our results suggest that the abnormal morphology of capillary ECs and thick BABs correlates with pulmonary artery remodeling and RVH. These ultrastructural changes might represent possible mechanisms of secondary pulmonary hypertension in BPD.

Proteolytic processing of cGMP-dependent protein kinase I mediates nuclear cGMP signaling in vascular smooth muscle cells.

Cyclic GMP modulates gene expression in vascular smooth muscle cells (SMCs) in part by stimulating cGMP-dependent protein kinase I (PKGI) and the phosphorylation of transcription factors. In some cells, cGMP increases nuclear translocation of PKGI and PKGI-dependent phosphorylation of transcription regulators; however, these observations have been variable, and the mechanisms mediating nuclear PKGI translocation are incompletely understood. We tested the hypothesis that proteolytic cleavage of PKGI is required for cGMP-stimulated nuclear compartmentation of PKGI and phosphorylation of transcription factors. We detected an NH(2)-terminal PKGI fragment with leucine zipper domain immunoreactivity in the cytosol and endoplasmic reticulum of SMCs, but only a COOH-terminal PKGI fragment containing the catalytic region (now termed PKGIgamma) was observed in the Golgi apparatus (GA) and nucleoplasm. Posttranslational PKGI processing in the GA was critical for nuclear compartmentation of PKGIgamma because GA disruption with nocodazol or brefeldin A inhibited PKGIgamma nuclear localization. PKGIgamma immunoreactivity was particularly abundant in the nucleolus of interphase SMCs where its colocalization with the nucleolar dense fibrillar component protein fibrillarin closely matched the level of nucleolar assembly. Purified nucleolar PKGIgamma enzyme activity was insensitive to cGMP stimulation, which is consistent with its lack of the NH(2)-terminal autoinhibitory domain. Mutation of a putative proteolytic cleavage region in PKGI inhibited cGMP-mediated phosphorylation of cAMP response element-binding protein, cAMP response element-dependent transcription, and nuclear localization of PKGIgamma. These observations suggest that posttranslational modification of PKGI critically influences the nuclear translocation of PKGI and activities of cGMP in SMCs.

Biopterin in the acute phase of hypoxia-ischemia in a neonatal pig model.

To clarify the participation of inducible NOS (iNOS) in the hypoxia-ischemia, we examined iNOS and its tetrahydrobiopterin co-factor in the cerebral cortex and plasma in a newborn-piglet model. We also investigated the role of hypothermia in iNOS expression and biopterin production. Male newborn piglets were ventilated 6% oxygen for 45 min. Their common carotid arteries were clamped during hypoxia. Then they were resuscitated with 30% oxygen (HI group). Piglets of the hypothermia group were treated as the HI group and their body was cooled to 35.5 degrees C after hypoxic-ischemic insults. Sham-treated piglets were also reserved. In the HI group, iNOS was present in neurons and macrophages of the cerebral cortex 12h after the insult. The concentrations of nitrite and nitrate were elevated in the cerebral cortex 12h after hypoxic-ischemic insults but the biopterin level was unchanged. The plasma biopterin concentration after the insult (377.9+/-78.7 nM) was five times higher than before the insult (80.1+/-4.3 nM); this level peaked 4h after the insult (604.8+/-200.9 nM) and only slightly decreased after 12h (445.9+/-57.8 nM). In the hypothermia group, no iNOS expression was observed 12h after the insult. The plasma biopterin concentration after the insult (464.2+/-92.3 nM) was similar to that in the HI group, but was suppressed by 4h of hypothermia (229.3+/-106.8 nM). In this study, neuronal iNOS expression and increase of NO production were found in the acute phase of hypoxia-ischemia. Brain biopterin did not increase in hypoxia-ischemia although plasma biopterin was five-fold elevated. The discrepancy may also affect hypoxic-ischemic organ damage.

TGF-beta-neutralizing antibodies improve pulmonary alveologenesis and vasculogenesis in the injured newborn lung.

Pulmonary injury is associated with the disruption of alveologenesis in the developing lung and causes bronchopulmonary dysplasia (BPD) in prematurely born infants. Transforming growth factor (TGF)-beta is an important regulator of cellular differentiation and early lung development, and its levels are increased in newborn lung injury. Although overexpression of TGF-beta in the lungs of newborn animals causes pathological features that are consistent with BPD, the role of endogenous TGF-beta in the inhibition of the terminal stage of lung development is incompletely understood. In this investigation, the hypothesis that O(2)-induced injury of the maturing lung is associated with TGF-beta-mediated disruption of alveologenesis and microvascular development was tested using a murine model of BPD. Here we report that treatment of developing mouse lungs with TGF-beta-neutralizing antibodies attenuates the increase in pulmonary cell phospho-Smad2 nuclear localization, which is indicative of augmented TGF-beta signaling, associated with pulmonary injury induced by chronic inhalation of 85% oxygen. Importantly, the neutralization of the abnormal TGF-beta activity improves quantitative morphometric indicators of alveologenesis, extracellular matrix assembly, and microvascular development in the injured developing lung. Furthermore, exposure to anti-TGF-beta antibodies is associated with improved somatic growth in hyperoxic mouse pups and not with an increase in pulmonary inflammation. These studies indicate that excessive pulmonary TGF-beta signaling in the injured newborn lung has an important role in the disruption of the terminal stage of lung development. In addition, they suggest that anti-TGF-beta antibodies may be an effective therapy for preventing some important developmental diseases of the newborn lung.

Contribution of pulmonary surfactant with inhaled nitric oxide for treatment of pulmonary hypertension.

BACKGROUND: Combined therapy of inhaled nitric oxide (iNO) with pulmonary surfactant replacement was reported to improve oxygenation in patients or animal models of persistent pulmonary hypertension of the newborn with pulmonary surfactant deficiency lung. To evaluate the potential of iNO for the treatment of persistent pulmonary hypertension of the newborn, pulmonary arterial pressure (PAP) was measured during iNO before and after pulmonary surfactant replacement in an animal model of pulmonary hypertension with surfactant deficiency. METHODS: Seven newborn piglets were injected with L-nitro-arginine-methylester to produce an animal model of pulmonary hypertension. After PAP increased, iNO (30 p.p.m.) was introduced. Then iNO was stopped, and animals were subjected to lung lavage with saline. After recording the effect of iNO, all animals then received exogenous pulmonary surfactant installation. After surfactant treatment, iNO was again introduced. RESULTS: Pulmonary arterial pressure and systemic arterial pressure were increased significantly by >30% after infusion of L-nitro-arginine-methylester. During iNO only PAP was reduced significantly. Respiratory system compliance decreased significantly after lung lavage, and increased significantly after pulmonary surfactant replacement with concomitant increase of PaO2. In contrast, significant reduction of PAP with iNO before and after pulmonary surfactant replacement were also observed. The reduction ratios of PAP under each condition were 75.2 +/- 7.4%, 81.3 +/- 3.1%, and 79.1 +/- 5.3%, respectively (not significant among conditions). CONCLUSION: These results suggest that iNO is still a potent pulmonary arterial vasodilator even under pulmonary surfactant deficiency in an animal model of pulmonary hypertension.