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Additives in vaping products, such as flavors, preservatives, or thickening agents, are commonly used to enhance user experience. Among these, Vitamin E acetate (VEA) was initially thought to be harmless but has been implicated as the primary cause of e-cigarette or vaping product use-associated lung injury, a serious lung disease. In our study, VEA serves as a proxy for other e-cigarette additives. To explore its harmful effects, we developed an exposure system to subject a pulmonary surfactant (PSurf) model to VEA-rich vapor. Through detailed analysis and atomic-level simulations, we found that VEA tends to cluster into aggregates on the PSurf surface, inducing deformations and weakening its essential elastic properties, critical for respiratory cycle function. Apart from VEA, our experiments also indicate that propylene glycol and vegetable glycerin, widely used in e-liquid mixtures, or their thermal decomposition products, alter surfactant properties. This research provides molecular-level insights into the detrimental impacts of vaping product additives on lung health. [ABSTRACT FROM AUTHOR]

Purpose: Improving the deep lung delivery of aerosol surfactant therapy (AST) with a dry powder formulation may enable significant reductions in dose while providing improved efficacy. The objective of Part I of this two-part study was to present the development of a new dry powder aerosol synthetic lung surfactant (SLS) product and to characterize performance based on aerosol formation and realistic in vitro airway testing leading to aerosol delivery recommendations for subsequent in vivo animal model experiments. Methods: A new micrometer-sized SLS excipient enhanced growth (EEG) dry powder formulation was produced via spray drying and aerosolized using a positive-pressure air-jet dry powder inhaler (DPI) intended for aerosol delivery directly to intubated infants with respiratory distress syndrome (RDS) or infant-size test animals. Results: The best-case design (D2) of the air-jet DPI was capable of high emitted dose (> 80% of loaded) and formed a < 2 µm mass median aerodynamic diameter (MMAD) aerosol, but was limited to ≤ 20 mg mass loadings. Testing with a realistic in vitro rabbit model indicated that over half of the loaded dose could penetrate into the lower lung regions. Using the characterization data, a dose delivery protocol was designed in which a 60 mg total loaded dose would be administered and deliver an approximate lung dose of 14.7–17.7 mg phospholipids/kg with a total aerosol delivery period < 5 min. Conclusions: A high-efficiency aerosol SLS product was designed and tested that may enable an order of magnitude reduction in administered phospholipid dose, and provide rapid aerosol administration to infants with RDS. [ABSTRACT FROM AUTHOR]

Lung type 2 pneumocytes (T2Ps) and alveolar macrophages (AMs) play crucial roles in the synthesis, recycling and catabolism of surfactant material, a lipid/protein fluid essential for respiratory function. The liver X receptors (LXR), LXRα and LXRβ, are transcription factors important for lipid metabolism and inflammation. While LXR activation exerts anti-inflammatory actions in lung injury caused by lipopolysaccharide (LPS) and other inflammatory stimuli, the full extent of the endogenous LXR transcriptional activity in pulmonary homeostasis is incompletely understood. Here, using mice lacking LXRα and LXRβ as experimental models, we describe how the loss of LXRs causes pulmonary lipidosis, pulmonary congestion, fibrosis and chronic inflammation due to defective de novo synthesis and recycling of surfactant material by T2Ps and defective phagocytosis and degradation of excess surfactant by AMs. LXR-deficient T2Ps display aberrant lamellar bodies and decreased expression of genes encoding for surfactant proteins and enzymes involved in cholesterol, fatty acids, and phospholipid metabolism. Moreover, LXR-deficient lungs accumulate foamy AMs with aberrant expression of cholesterol and phospholipid metabolism genes. Using a house dust mite aeroallergen-induced mouse model of asthma, we show that LXR-deficient mice exhibit a more pronounced airway reactivity to a methacholine challenge and greater pulmonary infiltration, indicating an altered physiology of LXR-deficient lungs. Moreover, pretreatment with LXR agonists ameliorated the airway reactivity in WT mice sensitized to house dust mite extracts, confirming that LXR plays an important role in lung physiology and suggesting that agonist pharmacology could be used to treat inflammatory lung diseases. [ABSTRACT FROM AUTHOR]

Purpose: Acute respiratory distress syndrome (ARDS) is a major cause of hypoxemic respiratory failure in adults. In ARDS extensive inflammation and leakage of fluid into the alveoli lead to dysregulation of pulmonary surfactant metabolism and function. Altered surfactant synthesis, secretion, and breakdown contribute to the clinical features of decreased lung compliance and alveolar collapse. Lung function in ARDS could potentially be restored with surfactant replacement therapy, and synthetic surfactants with modified peptide analogues may better withstand inactivation in ARDS alveoli than natural surfactants. Methods: This study aimed to investigate the activity in vitro and the bolus effect (200 mg phospholipids/kg) of synthetic surfactant CHF5633 with analogues of SP‐B and SP‐C, or natural surfactant Poractant alfa (Curosurf®, both preparations Chiesi Farmaceutici S.p.A.) in a severe ARDS model (the ratio of partial pressure arterial oxygen and fraction of inspired oxygen, P/F ratio ≤ 13.3 kPa) induced by hydrochloric acid instillation followed by injurious ventilation in adult New Zealand rabbits. The animals were ventilated for 4 h after surfactant treatment and the respiratory parameters, histological appearance of lung parenchyma and levels of inflammation, oxidative stress, surfactant dysfunction, and endothelial damage were evaluated. Results: Both surfactant preparations yielded comparable improvements in lung function parameters, reductions in lung injury score, pro-inflammatory cytokines levels, and lung edema formation compared to untreated controls. Conclusions: This study indicates that surfactant replacement therapy with CHF5633 improves lung function and lung architecture, and attenuates inflammation in severe ARDS in adult rabbits similarly to Poractant alfa. Clinical trials have so far not yielded conclusive results, but exogenous surfactant may be a valid supportive treatment for patients with ARDS given its anti-inflammatory and lung-protective effects. [ABSTRACT FROM AUTHOR]

Purpose: This study investigates how surfactants affect the in-vitro anti-infective efficacy of micafungin, caspofungin, anidulafungin, and amphotericin B in treating pulmonary mycoses. Methods: MIC values for antifungal agents were determined against Candida krusei (now Pichia kudriavzevii) ATCC 6258, Candida albicans ATCC 90028, and 18 clinical isolates using the broth microdilution method in RPMI medium, following EUCAST recommendations. MIC assays included testing with and without Curosurf® surfactant at 1 mg/mL for C. krusei ATCC 6258 and all C. krusei isolates. Subsequent Time-kill studies in Sabouraud broth involved testing both C. albicans ATCC 90028 and C. krusei ATCC 6258 strains at concentrations equal their respective MIC values, with and without surfactant, using all four antifungals. CFU/mL were assessed at multiple time points up to 24 h. TKCs with different surfactant concentrations for C. krusei ATCC 6258 and mini-TKCs at various concentrations relative to the MIC of C. krusei isolates and the reference strain were conducted with micafungin, anidulafungin, and caspofungin. Results: MIC results showed that 1 µg/mL surfactant reduced killing of micafungin and anidulafungin against C. krusei, while caspofungin was unaffected. Amphotericin B's MIC decreased by half. TKCs demonstrated significant effects of surfactant on micafungin and anidulafungin against C. krusei, with complete abolition of anidulafungin's activity against C. albicans. Conclusion: This in-vitro study highlights the concentration-dependent inhibitory effect of surfactant on antifungal activity against C. krusei and, to some extent, C. albicans, necessitating further clinical validation for invasive lung mycoses treatment. [ABSTRACT FROM AUTHOR]

Background: We assessed the incidence of and risk factors for acute kidney injury (AKI) in very low birthweight infants (VLBW) in a center with a specific neonatal management protocol focusing on avoidance of early mechanical ventilation (MV). Methods: This retrospective single center analysis includes 128 infants born in 2020 with a gestational age ≥ 22 weeks who were screened for AKI using the nKDIGO criteria. Results: AKI was identified in 25/128 patients (19.5%) with eight of them (6.3%) presenting with severe AKI. Low gestational age, birthweight and 10-minute Apgar score as well as high CRIB-1 score were all associated with incidence of AKI. Forty-five percent of the infants with MV developed AKI vs. 8.9% of those without MV (p < 0.001). Early onset of MV and administration of more than 3 dosages of NSAIDs for patent duct were identified as independent risk factors for AKI in a logistic regression analysis. Conclusions: We report a substantially lower frequency of AKI in VLBW infants as compared to previous studies, along with a very low rate of MV. A neonatal protocol focusing on avoidance of MV within the first days of life may be a key factor to decrease the risk of AKI in immature infants. [ABSTRACT FROM AUTHOR]

The main component of pulmonary surfactant is dipalmitoyl phosphatidylcholine (DPPC), which reduces the surface tension almost to zero when the lung surface is compressed, thus preventing the alveolus from collapse in the course of exhalation. In this work the methods of the surface rheology have been employed to determine the influence of six pulmonary lipids on the dynamic surface properties of a DPPC monolayer at different temperatures and in a wide range of surface tensions. Particular attention has been paid to the region of low surface tensions (lower than 25 mN/m) at temperatures of 25 and 35°С, with these conditions being close to the physiological state on the internal surface of lungs. The addition of lipids with similar molecular structures to DPPC does not affect significantly the dynamic surface properties at a temperature of 25°C. At the same time, the addition of these lipids increases the surface elasticity in the region of low surface tensions at 35°С. However, under these conditions, the presence of lipids with unsaturated hydrocarbon radicals in the surface layer leads to the opposite effect and hinders the achievement of low surface tensions during slow compression. The results obtained have shown the possibility to control the properties of the lipid/DPPC mixed monolayer, which can be considered which can be considered as a model of pulmonary surfactant. [ABSTRACT FROM AUTHOR]

Glucose homeostasis is maintained by hormones secreted from different cell types of the pancreatic islets and controlled by manifold input including signals mediated through G protein-coupled receptors (GPCRs). RNA-seq analyses revealed expression of numerous GPCRs in mouse and human pancreatic islets, among them Gpr116/Adgrf5. GPR116 is an adhesion GPCR mainly found in lung and required for surfactant secretion. Here, we demonstrate that GPR116 is involved in the somatostatin release from pancreatic delta cells using a whole-body as well as a cell-specific knock-out mouse model. Interestingly, the whole-body GPR116 deficiency causes further changes such as decreased beta-cell mass, lower number of small islets, and reduced pancreatic insulin content. Glucose homeostasis in global GPR116-deficient mice is maintained by counter-acting mechanisms modulating insulin degradation. Our data highlight an important function of GPR116 in controlling glucose homeostasis. In vitro, ex vivo, and in vivo analysis shows that the Adhesion GPCR ADGRF5/GPR116 regulates islet functionality. Activation of the receptor leads to an increase in somatostatin secretion whereas loss of the receptor results in metabolic changes. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to understand how coating with a pulmonary surfactant, namely Alveofact, affects the physicochemical parameters as well as in vitro behavior of polyethylenimine (PEI) polyplexes for pulmonary siRNA delivery. Methods: Alveofact-coated polyplexes were prepared at different Alveofact:PEI coating ratios and analyzed in terms of size, PDI and zeta potential as well as morphology by transmission electron microscopy. The biological behavior was evaluated in a lung epithelial cell line regarding cell viability, cellular uptake via flow cytometry and gene downregulation by qRT-PCR. Furthermore, a 3D ALI culture model was established to test the mucus diffusion and cellular uptake by confocal microscopy as well as gene silencing activity by qRT-PCR. Results: After optimizing the coating process by testing different Alveofact:PEI coating ratios, a formulation with suitable parameters for lung delivery was obtained. In lung epithelial cells, Alveofact-coated polyplexes were well tolerated and internalized. Furthermore, the coating improved the siRNA-mediated gene silencing efficiency. Alveofact-coated polyplexes were then tested on a 3D air-liquid interface (ALI) culture model that, by expressing tight junctions and secreting mucus, resembles important traits of the lung epithelium. Here, we identified the optimal Alveofact:PEI coating ratio to achieve diffusion through the mucus layer while retaining gene silencing activity. Interestingly, the latter underlined the importance of establishing appropriate in vitro models to achieve more consistent results that better predict the in vivo activity. Conclusion: The addition of a coating with pulmonary surfactant to polymeric cationic polyplexes represents a valuable formulation strategy to improve local delivery of siRNA to the lungs. [ABSTRACT FROM AUTHOR]

To understand the nature of xenon-induced recovery of the functional activity of pulmonary surfactant during inhalation of a gas mixture of Xe/O2, the mechanisms of the ongoing processes were studied in silico. Impaired ability of pulmonary surfactant to maintain low surface tension preventing alveolar atelectasis occurs due to formation of aggregates of its phospholipids and a decrease in their lateral mobility. Aggregated lipid systems, whose structure can explain the loss of lateral mobility of surfactant phospholipids, were modeled in silico at the molecular level. Changes in the Gibbs energy and enthalpy in the reactions of the formation and decomposition of xenon intermediates with model systems of various compositions/structures were calculated. The simulation was carried out for atomic xenon and for xenon polarized by molecular oxygen in the gas phase and taking into account solvation with water. The loss of lateral mobility of phospholipids can be explained by specific features of electronic structure of hydrophobic hydrocarbon molecules (acyl chains), which, under certain conditions, are capable of forming structured common regions of the electrostatic potential, to which xenon has an affinity. In this case, inclusion coordination compounds of the "guest—host" type are formed, which subsequently decompose due to the nature of the polarization of the Xe atoms. The formation and decomposition of xenon intermediates in these systems lead to recovery of the lateral mobility (fluidity) of phospholipids, which restores functional activity of surfactant films. [ABSTRACT FROM AUTHOR]

Respecting patient autonomy through the process of soliciting informed consent is a cornerstone of clinical ethics. In pediatrics, until a child becomes an adult or legally emancipated, that ethical tenet takes the form of respect for parental decision-making authority. In instances of respecting religious beliefs, doing so is not always apparent and sometimes the challenge lies not only in the healthcare provider's familiarity of religious restrictions but also their knowledge of medical interventions themselves which might conflict with those restrictions. We examine a case of a newborn receiving animal-derived surfactant, a common scenario in neonatology, and present considerations for providers to weigh when confronting when such an intervention might conflict with parent's religious beliefs. We end with strategizing ways to address this issue as a medical community. [ABSTRACT FROM AUTHOR]

The mammalian lungs encounter several pathogens, but have a sophisticated multi-phase immune defense. Furthermore, several immune responses to suppress pulmonary pathogens can damage the airway epithelial cells, particularly the vital alveolar epithelial cells (pneumocytes). The lungs have a sequentially activated, but overlapping, five phase immune response to suppress most pathogens, while causing minimal damage to the airway epithelial cells. Each phase of the immune response may suppress the pathogens, but if the previous phase proves inadequate, a stronger phase of immune response is activated, but with an increased risk of airway epithelial cell damage. The first phase immune response involves the pulmonary surfactants, which have proteins and phospholipids with potentially sufficient antibacterial, antifungal and antiviral properties to suppress many pathogens. The second phase immune response involves the type III interferons, having pathogen responses with comparatively minimal risk of damage to airway epithelial cells. The third phase immune response involves type I interferons, which implement stronger immune responses against pathogens with an increased risk of damage to airway epithelial cells. The fourth phase immune response involves the type II interferon, interferon-γ, which activates stronger immune responses, but with considerable risk of airway epithelial cell damage. The fifth phase immune response involves antibodies, potentially activating the complement system. In summary, five major phases of immune responses for the lungs are sequentially initiated to create an overlapping immune response which can suppress most pathogens, while usually causing minimal damage to the airway epithelial cells, including the pneumocytes. [ABSTRACT FROM AUTHOR]

Pulmonary surfactant, which is a complex mixture of lipids and proteins, plays a key role in the functional properties of the respiratory system. Lipids form complexes with proteins to maintain low values of surface tension at continuous compression/expansion deformations. However, interactions that lead to the complexation still remain to be unknown thus significantly hampering the development of synthetic analogs of the natural pulmonary surfactant. In this work, the methods of surface rheology and ellipsometry have been employed to study the dynamic properties of model phospholipid monolayers applied onto the surfaces of synthetic polyelectrolyte solutions. It has been shown, that electrostatic or hydrophobic interactions between lipids and macromolecules are insufficient for the efficient complexation and maintenance of low surface tension values. [ABSTRACT FROM AUTHOR]

A brief review of the studies in the field of bioorganic materials science, performed at the "Langmuir" beamline of the Kurchatov Synchrotron Radiation Source (KSRS), is presented. The specificity of the beamline infrastructure is discussed, and the main X-ray optical characteristics of the system are reported. The research potential of the beamline is demonstrated by an example of a series of experiments aimed at studying the mechanisms of damage of the molecular organization of pulmonary surfactant caused by nanoaerosol particles. Particular attention is paid to the experimental implementation of X-ray absorption spectroscopy (XAS) for measurements on liquid surfaces. The results of in situ studies of the change in the valence state of cerium ions on the air–liquid interface are reported. [ABSTRACT FROM AUTHOR]

Alveolar macrophages (AM) hold lung homeostasis intact. In addition to the defense against inhaled pathogens and deleterious inflammation, AM also maintain pulmonary surfactant homeostasis, a vital lung function that prevents pulmonary alveolar proteinosis. Signals transmitted between AM and pneumocytes of the pulmonary niche coordinate these specialized functions. However, the mechanisms that guide the metabolic homeostasis of AM remain largely elusive. We show that the NK cell-associated receptor, NKR-P1B, is expressed by AM and is essential for metabolic programming. Nkrp1b−/− mice are vulnerable to pneumococcal infection due to an age-dependent collapse in the number of AM and the formation of lipid-laden AM. The AM of Nkrp1b−/− mice show increased uptake but defective metabolism of surfactant lipids. We identify a physical relay between AM and alveolar type-II pneumocytes that is dependent on pneumocyte Clr-g expression. These findings implicate the NKR-P1B:Clr-g signaling axis in AM-pneumocyte communication as being important for maintaining metabolism in AM. Alveolar macrophages (AM) in the lungs maintain surfactant during homeostasis and respond to infectious pathogens. Here the authors show that in the absence of NKR-P1B, pneumococcal infection is more severe because KO AM have increased rates of lipid surfactant uptake and reduced anti-microbial function. [ABSTRACT FROM AUTHOR]

The document is a correction notice for an article titled "Development of a New Dry Powder Aerosol Synthetic Lung Surfactant Product for Neonatal Respiratory Distress Syndrome (RDS) – Part I: In Vitro Testing and Characterization." The correction includes the addition of author Robert M. DiBlasi's middle initial, which was incorrectly published as "Robert DiBlasi." The article is licensed under a Creative Commons Attribution 4.0 International License. The document also provides contact information for Worth Longest, the corresponding author. [Extracted from the article]

Purpose: Surfactant therapy incorporates liquid bolus instillation via endotracheal tube catheter and a mechanical ventilator in preterm neonates with respiratory distress syndrome (RDS). Aerosolized surfactants have generated interest and conflicting data on the efficacy of phospholipid (PL) dose requirements. We developed and characterized a synthetic lung surfactant excipient enhanced growth (SLS-EEG) dry powder aerosol product. In this study, we compare the in vivo performance of the new aerosol product with standard-of-care liquid instillation.Juvenile rabbits were sedated, anesthetized, intubated, and ventilated. Endogenous surfactant was depleted via whole lung lavage. Animals received either a standard dose of liquid Curosurf (200 mg PL/kg) instilled via a tracheal catheter, SLS-EEG powder aerosol (60 mg device loaded dose; equivalent to 24 mg PL/kg), or sham control. Gas exchange, lung compliance, and indices of disease severity were recorded every 30 min for 3.5 h and macro- and microscopy images were acquired at necropsy.While aerosol was administered at an approximately tenfold lower PL dose, both liquid-instilled and aerosol groups had similar, nearly complete recoveries of arterial oxygenation (PaO2; 96–100% recovery) and oxygenation index, and the aerosol group had superior recovery of compliance (P < 0.05). The SLS-EEG aerosol group showed less lung tissue injury, greater uniformity in lung aeration, and more homogenous surfactant distribution at the alveolar surfaces compared with liquid Curosurf.The new dry powder aerosol SLS product (which includes the delivery strategy, formulation, and delivery system) has the potential to be a safe, effective, and economical alternative to the current clinical standard of liquid bolus surfactant instillation.Methods: Surfactant therapy incorporates liquid bolus instillation via endotracheal tube catheter and a mechanical ventilator in preterm neonates with respiratory distress syndrome (RDS). Aerosolized surfactants have generated interest and conflicting data on the efficacy of phospholipid (PL) dose requirements. We developed and characterized a synthetic lung surfactant excipient enhanced growth (SLS-EEG) dry powder aerosol product. In this study, we compare the in vivo performance of the new aerosol product with standard-of-care liquid instillation.Juvenile rabbits were sedated, anesthetized, intubated, and ventilated. Endogenous surfactant was depleted via whole lung lavage. Animals received either a standard dose of liquid Curosurf (200 mg PL/kg) instilled via a tracheal catheter, SLS-EEG powder aerosol (60 mg device loaded dose; equivalent to 24 mg PL/kg), or sham control. Gas exchange, lung compliance, and indices of disease severity were recorded every 30 min for 3.5 h and macro- and microscopy images were acquired at necropsy.While aerosol was administered at an approximately tenfold lower PL dose, both liquid-instilled and aerosol groups had similar, nearly complete recoveries of arterial oxygenation (PaO2; 96–100% recovery) and oxygenation index, and the aerosol group had superior recovery of compliance (P < 0.05). The SLS-EEG aerosol group showed less lung tissue injury, greater uniformity in lung aeration, and more homogenous surfactant distribution at the alveolar surfaces compared with liquid Curosurf.The new dry powder aerosol SLS product (which includes the delivery strategy, formulation, and delivery system) has the potential to be a safe, effective, and economical alternative to the current clinical standard of liquid bolus surfactant instillation.Results: Surfactant therapy incorporates liquid bolus instillation via endotracheal tube catheter and a mechanical ventilator in preterm neonates with respiratory distress syndrome (RDS). Aerosolized surfactants have generated interest and conflicting data on the efficacy of phospholipid (PL) dose requirements. We developed and characterized a synthetic lung surfactant excipient enhanced growth (SLS-EEG) dry powder aerosol product. In this study, we compare the in vivo performance of the new aerosol product with standard-of-care liquid instillation.Juvenile rabbits were sedated, anesthetized, intubated, and ventilated. Endogenous surfactant was depleted via whole lung lavage. Animals received either a standard dose of liquid Curosurf (200 mg PL/kg) instilled via a tracheal catheter, SLS-EEG powder aerosol (60 mg device loaded dose; equivalent to 24 mg PL/kg), or sham control. Gas exchange, lung compliance, and indices of disease severity were recorded every 30 min for 3.5 h and macro- and microscopy images were acquired at necropsy.While aerosol was administered at an approximately tenfold lower PL dose, both liquid-instilled and aerosol groups had similar, nearly complete recoveries of arterial oxygenation (PaO2; 96–100% recovery) and oxygenation index, and the aerosol group had superior recovery of compliance (P < 0.05). The SLS-EEG aerosol group showed less lung tissue injury, greater uniformity in lung aeration, and more homogenous surfactant distribution at the alveolar surfaces compared with liquid Curosurf.The new dry powder aerosol SLS product (which includes the delivery strategy, formulation, and delivery system) has the potential to be a safe, effective, and economical alternative to the current clinical standard of liquid bolus surfactant instillation.Conclusions: Surfactant therapy incorporates liquid bolus instillation via endotracheal tube catheter and a mechanical ventilator in preterm neonates with respiratory distress syndrome (RDS). Aerosolized surfactants have generated interest and conflicting data on the efficacy of phospholipid (PL) dose requirements. We developed and characterized a synthetic lung surfactant excipient enhanced growth (SLS-EEG) dry powder aerosol product. In this study, we compare the in vivo performance of the new aerosol product with standard-of-care liquid instillation.Juvenile rabbits were sedated, anesthetized, intubated, and ventilated. Endogenous surfactant was depleted via whole lung lavage. Animals received either a standard dose of liquid Curosurf (200 mg PL/kg) instilled via a tracheal catheter, SLS-EEG powder aerosol (60 mg device loaded dose; equivalent to 24 mg PL/kg), or sham control. Gas exchange, lung compliance, and indices of disease severity were recorded every 30 min for 3.5 h and macro- and microscopy images were acquired at necropsy.While aerosol was administered at an approximately tenfold lower PL dose, both liquid-instilled and aerosol groups had similar, nearly complete recoveries of arterial oxygenation (PaO2; 96–100% recovery) and oxygenation index, and the aerosol group had superior recovery of compliance (P < 0.05). The SLS-EEG aerosol group showed less lung tissue injury, greater uniformity in lung aeration, and more homogenous surfactant distribution at the alveolar surfaces compared with liquid Curosurf.The new dry powder aerosol SLS product (which includes the delivery strategy, formulation, and delivery system) has the potential to be a safe, effective, and economical alternative to the current clinical standard of liquid bolus surfactant instillation. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible pulmonary interstitial disease that seriously affects the patient's quality of life and lifespan. The pathogenesis of IPF has not been clarified, and its treatment is limited to pirfenidone and nintedanib, which only delays the decline of lung function. Alveolar epithelial type 2 (AT2) cells are indispensable in the regeneration and lung surfactant secretion of alveolar epithelial cells. Studies have shown that AT2 cell dysfunction initiates the occurrence and progression of IPF. This review expounds on the AT2 cell dysfunction in IPF, involving senescence, apoptosis, endoplasmic reticulum stress, mitochondrial damage, metabolic reprogramming, and the transitional state of AT2 cells. This article also briefly summarizes potential treatments targeting AT2 cell dysfunction. [ABSTRACT FROM AUTHOR]

To provide novel data on surfactant levels in adult COVID-19 patients, we collected bronchoalveolar lavage fluid less than 72 h after intubation and used Fourier Transform Infrared Spectroscopy to measure levels of dipalmitoylphosphatidylcholine (DPPC). A total of eleven COVID-19 patients with moderate-to-severe ARDS (CARDS) and 15 healthy controls were included. CARDS patients had lower DPPC levels than healthy controls. Moreover, a principal component analysis was able to separate patient groups into distinguishable subgroups. Our findings indicate markedly impaired pulmonary surfactant levels in COVID-19 patients, justifying further studies and clinical trials of exogenous surfactant. [ABSTRACT FROM AUTHOR]

There is no firm consensus about the optimal technique for the administration of exogenous surfactant in preterm neonates, and different techniques may be equally effective. The intubation-surfactant-extubation (INSURE) procedure has not been fully described, and important details, such as duration and mode of ventilation, remain unclear, leading to significant clinical practice variations and influencing its suitability and feasibility. Since the first INSURE description, our knowledge in respiratory care has largely progressed, but the technique has not been updated according to current evidence-based practice. Thus, our aim is to formally describe a modern way to perform INSURE, based on the current knowledge and technology, to increase its feasibility and patients' safety. We offer ENSURE (Enhanced INSURE) as an updated and standardised technique for surfactant administration, clarifying crucial issues of the original method by applying current state-of-the-art concepts of respiratory care. We performed a cross-sectional observational study enrolling 57 preterm neonates describing ENSURE feasibility and safety. Conclusion: ENSURE can be used as a reference technique in clinical practice, teaching and research. What is Known: • There is no consensus about the optimal method for surfactant administration. INSURE technique has been originally described many years ago without considering modern principles of neonatal respiratory care and the available state-of-the-art technology. What is New: • We here describe a modern way to perform INSURE, based on the current knowledge and technology. We called it ENSURE (Enhanced INSURE) and clarified crucial points of the original technique, in light of the current knowledge. We verified feasibility and safety of ENSURE in a cross-sectional observational study enrolling 57 preterm neonates. [ABSTRACT FROM AUTHOR]

In preterm premature rupture of membranes (PPROM), a decision between early delivery with prematurity complications and pregnancy prolongation bearing the risk of chorioamnionitis has to be made. To define disadvantages of delayed prolongation, latency duration of PPROM in expectantly managed pregnancies was investigated. We included those PPROMs > 48 h leading to preterm birth prior 37 weeks' gestation and retrospectively analyzed 84 preterm infants fulfilling these criteria. The association between latency duration/appearance of PPROM and respiratory outcome (primary outcomes) and neurological outcome (secondary outcomes) was investigated. The study showed that latency duration of PPROM is not associated with clinical or histological chorioamnionitis (p = 0.275; p = 0.332). As the numerous clinical parameters show multicollinearity between each other, we performed a multiple regression analysis to consider this fact. Respiratory distress syndrome is significantly associated with gestational age at PPROM (p < 0.001), and surfactant application is significantly associated with PPROM duration (p = 0.014). The other respiratory parameters including steroids and diuretics therapy, bronchopulmonary dysplasia, and the neurological parameters (intraventricular hemorrhage, Bayley II testing at a corrected age of 24 months) were not significantly associated with PPROM duration or gestational age at PPROM diagnosis. Conclusion: Latency duration of PPROM was not associated with adverse neonatal outcome in expectantly and carefully managed pregnancies, but respiratory distress syndrome was pronounced. The observed effect of pronounced respiratory distress syndrome can be treated with surfactant preparations and was not followed by increased rate of bronchopulmonary dysplasia. What is Known: • In case of preterm premature rupture of membranes, a decision between pregnancy prolongation with the risk of chorioamnionitis and early delivery with prematurity complications has to be made. • Chorioamnionitis is a dangerous situation for the pregnant woman and the fetus. • Impaired neurodevelopmental outcome is strongly correlated with pronounced prematurity due to the increased rate of serious complications. What is New: • Respiratory distress syndrome is significantly associated with gestational age at PPROM, and surfactant application is significantly associated with PPROM duration. • Latency duration of PPROM is not associated with adverse respiratory neonatal outcome (therapy with continuous positive airway pressure, therapy with diuretics and/or steroids, bronchopulmonary dysplasia) in expectantly and carefully managed pregnancies. • Intraventricular hemorrhage and Bayley II testing at a corrected age of 24 months are not associated with latency duration of PPROM when pregnancies are carefully observed. [ABSTRACT FROM AUTHOR]

The article presents a theoretical rationale and a clinical case of relief of post-COVID ventilation failure by inhalation of Xe and O2 gas mixture. Pneumonitis of coronavirus etiology transforms saturated phospholipids of surfactant into a solid-ordered phase, which disrupts surface tension, alveolar pneumatization, and alveolar-capillary gas exchange. Using molecular modeling (B3LYP/lanl2dz; GAUSSIAN09), we demonstrated that Xe atom due to the van der Waals dispersion interaction increases the distance between the phospholipid acyl chains providing a phase transition from the solid-ordered to liquid phase and restored the surface-active monolayer surfactant film. A clinical case confirmed that short-term inhalations of the Xe and O2 gas mixture relieved manifestations of ventilation insufficiency and increased SpO2 and pneumatization of the terminal parts of the lungs. [ABSTRACT FROM AUTHOR]

Background: Lung inflammation is associated with many respiratory conditions. Consequently, anti-inflammatory medications, like glucocorticoids, have become mainstay intrapulmonary therapeutics. However, their effectiveness for treating inflammation occurring in the alveolar regions of the lung is limited by suboptimal delivery. To improve the pulmonary distribution of glucocorticoids, such as budesonide to distal regions of the lung, exogenous surfactant has been proposed as an ideal delivery vehicle for such therapies. It was therefore hypothesized that fortifying an exogenous surfactant (BLES) with budesonide would enhance efficacy for treating pulmonary inflammation in vivo. Methods: An intratracheal instillation of heat-killed bacteria was used to elicit an inflammatory response in the lungs of male and female rats. Thirty minutes after this initial instillation, either budesonide or BLES combined with budesonide was administered intratracheally. To evaluate the efficacy of surfactant delivery, various markers of inflammation were measured in the bronchoalveolar lavage and lung tissue. Results: Although budesonide exhibited anti-inflammatory effects when administered alone, delivery with BLES enhanced those effects by lowering the lavage neutrophil counts and myeloperoxidase activity in lung tissue. Combining budesonide with BLES was also shown to reduce several other pro-inflammatory mediators. These results were shown across both sexes, with no observed sex differences. Conclusion: Based on these findings, it was concluded that exogenous surfactant can enhance the delivery and efficacy of budesonide in vivo. [ABSTRACT FROM AUTHOR]

Lung surfactant accumulates in the lamellar body (LB) via not only the secretory (anterograde) pathway but also the endocytic (retrograde) pathway. Our previous studies suggested that the major surfactant components, phosphatidylcholine and surfactant protein A take independent trafficking routes in alveolar type II cells. Thus, trafficking of surfactant protein B (SP-B), a major hydrophobic surfactant apoprotein, should be re-evaluated by a straightforward method. Radiolabeling of cells and subsequent cell fractionation were employed to pursue the sequential trafficking of newly synthesized SP-B in rabbit alveolar type II cells. The LB fraction was prepared by gradient ultracentrifugation. Immunoprecipitation from the culture medium, total cells, and LB fraction was carried out with anti-SP-B antibody. Newly synthesized [35S]-pro-SP-B (~ 42 kDa) was detected in the cells after 1 h. An ~ 8-kDa mature form of [35S]-SP-B was detected in the cells after 3 h and in the LB after 6 h. Mature [35S]-SP-B was predominant in the cells after 24 h, and the dominant portion was present in the LB. In contrast, only a small amount of mature [35S]-SP-B was present in the culture medium. Molecular processing of ~ 42 kDa [35S]-pro-SP-B and transport to the LB was inhibited by brefeldin A, which disassembles the Golgi apparatus. These results suggest that newly synthesized SP-B is sorted to the LB via the Golgi and stored until exocytosis. This pathway is distinct from the pathways reported for phosphatidylcholine and surfactant protein A. [ABSTRACT FROM AUTHOR]

The guidelines for surfactant therapy are largely based on studies done in developed coun1tries wherein the facility infrastructure, patient profile, and clinical practices are different from low- and middle-income countries (LMICs). Though SRT is widely practiced in developing countries, there exists variability in clinical practice. Our objective was to identify the factors which would predict the need of surfactant administration and develop a "clinical respiratory distress (RD) score" for surfactant administration in preterm neonates with respiratory distress. A prospective observational study was conducted in 153 preterm infants (260/7 to 346/7 weeks gestation) with respiratory distress who were managed with CPAP and/or surfactant where indicated. Gestation < 32 weeks, no antenatal corticosteroid (ANS), hypothermia at admission, Apgar score < 3 at 1 minute, and Silverman score > 2 at 2 hours were found to be the significant factors in predicting surfactant requirement in multivariate regression analysis. A seven point scale was developed and categorized into two categories as < 4 and ≥ 4. The sensitivity, specificity, PPV, and NPV were 67%, 87%, 86%, and 68%, respectively, with a cutoff score ≥ 4. The positive likelihood ratio was 5.07 (95% CI 2.71-9.48), and negative likelihood ratio was 0.38 (95% CI 0.28-0.52). The observed rate of surfactant administration was found to be around 32% when the composite score was below four, and the rate increased to almost 86% when the composite score was ≥ 4. The predictive accuracy of the model was subsequently evaluated in a cohort of 56 preterm infants with respiratory distress.. Sensitivity, specificity and positive and negative predictive value during the validation phase were 97%, 73%, 85%, and 94%, respectively. With a composite score less than 4, the observed rate of surfactant administration was 6% (95% CI 1%-28%) as against the model predicted rate of 24%, while with composite score ≥ 4, the observed rate was 85% (95% CI 69%-94%) as against the model predicted rate of 90%.Conclusion: "Clinical RD score" is a simple score, which can be utilized for decision-making for early surfactant administration for preterm infants (260/7 to 346/7 weeks gestation) with respiratory distress.Trial Registration: NCT03273764What is Known:• Both CPAP and surfactant therapy are effective in management of preterm infants with RDS.• The efficacy of surfactant replacement therapy is better when it is administered early in the course of disease.What is New:• Many of the known risk factors for RDS do not predict surfactant requirement.• "Composite RD score" comprising of five independent predictors of surfactant requirement with a numeric cutoff may help decide which preterm neonates with respiratory distress need early surfactant administration in low- and middle-income countries. [ABSTRACT FROM AUTHOR]

Lipid-protein complexes are the basis of pulmonary surfactants covering the respiratory surface and mediating gas exchange in lungs. Cardiolipin is a mitochondrial lipid overexpressed in mammalian lungs infected by bacterial pneumonia. In addition, increased oxygen supply (hyperoxia) is a pathological factor also critical in bacterial pneumonia. In this paper we fabricate a micrometer-size graphene-based sensor to measure oxygen permeation through pulmonary membranes. Combining oxygen sensing, X-ray scattering, and Atomic Force Microscopy, we show that mammalian pulmonary membranes suffer a structural transformation induced by cardiolipin. We observe that cardiolipin promotes the formation of periodic protein–free inter–membrane contacts with rhombohedral symmetry. Membrane contacts, or stalks, promote a significant increase in oxygen gas permeation which may bear significance for alveoli gas exchange imbalance in pneumonia. Changes in the pulmonary membrane, caused by bacterial infection, form part of the pathology of pneumonia. Here, the authors report on a graphene-based oxygen sensor which is used along with X-ray diffraction and AFM to measure the structural changes and changes in oxygen permeability of pulmonary membranes associated with bacterial pneumonia. [ABSTRACT FROM AUTHOR]

Lung surfactants are used for reducing alveolar surface tension in preterm infants to ease breathing. Phospholipid films with surfactant proteins regulate the activity of alveolar macrophages and reduce inflammation. Aberrant skin wound healing is characterized by persistent inflammation. The aim of the study was to investigate if lung surfactant can promote wound healing. Preclinical wound models, e.g. cell scratch assays and full-thickness excisional wounds in mice, and a randomized, phase I clinical trial in healthy human volunteers using a suction blister model were used to study the effect of the commercially available bovine lung surfactant on skin wound repair. Lung surfactant increased migration of keratinocytes in a concentration-dependent manner with no effect on fibroblasts. Significantly reduced expression levels were found for pro-inflammatory and pro-fibrotic genes in murine wounds. Because of these beneficial effects in preclinical experiments, a clinical phase I study was initiated to monitor safety and tolerability of surfactant when applied topically onto human wounds and normal skin. No adverse effects were observed. Subepidermal wounds healed significantly faster with surfactant compared to control. Our study provides lung surfactant as a strong candidate for innovative treatment of chronic skin wounds and as additive for treatment of burn wounds to reduce inflammation and prevent excessive scarring. [ABSTRACT FROM AUTHOR]

Lung ultrasound (LUS) has been described as a useful tool in early prognosis of several respiratory diseases of the newborn, especially preterm infant newborns (PTNB) with respiratory distress syndrome (RDS), but still, it is not a standard of care in many neonatal units. We have conducted a descriptive, prospective study in a tertiary neonatal unit during 1 year. PTNB less than 35 weeks with respiratory distress at birth on non-invasive ventilation were recruited. A LUS was performed in the first 12 h of life and scored from 6 to 18 points (6 areas, 1 to 3 points each). They were followed until discharge. Main outcomes: need for surfactant treatment. Sixty-four preterm infants, median gestational age 29 weeks. Median LUS score in surfactant group was significantly higher than in no surfactant group (p < 0.0001). LUS ROC curve for surfactant treatment shows AUC 0.97 (IC 95% 0.92-1). LUS Odds ratio for surfactant treatment 3.17 (IC 95% 1.36-7.35).Conclusion: Early high LUS score correlates with surfactant necessity in preterm infants with respiratory distress at birth.What is Known:• Lung ultrasound (LUS) is a useful tool in determining prognosis of preterm infants with respiratory distress at birth.What is New:• This study adds evidence about LUS and preterm infants with respiratory distress, early predicting surfactant need and mechanical ventilation. [ABSTRACT FROM AUTHOR]

We evaluated the efficiency of a lubricant based on a pulmonary surfactant in experimental knee osteoarthritis in rats induced by intraarticular injection of abrasive material that reduces the lubricative properties of the synovial fluid. Experimental substance containing proteins of the pulmonary surfactant exhibiting natural lubricative properties was used as the lubricant. The effectiveness of the substance was analyzed by changes in morphological characteristics of the articular cartilage in 3D reconstruction images of the knee joint obtained by the method of multiple high-precision grinding. It was found that radial thickness of the articular cartilage increased and surface relief index decreased on the 6th and 12th week after administration of the substance containing surfactant proteins, which can indicate partial recovery of the articular cartilage. [ABSTRACT FROM AUTHOR]

An exacerbated amount of neutrophil extracellular traps (NETs) can cause dysfunction of systems during inflammation. However, host proteins and factors that suppress NET formation (NETosis) are not clearly identified. Here we show that an innate immune collectin, pulmonary surfactant protein-D (SP-D), attenuates lipopolysaccharide (LPS)-mediated NETosis in human neutrophils by binding to LPS. SP-D deficiency in mice (Sftpd−/−) leads to excess NET formation in the lungs during LPS-mediated inflammation. In the absence of SP-D, NETs inhibit the surface-active properties of lung surfactant, essential to prevent the collapse of alveoli, the air breathing structures of the lungs. SP-D reverses NET-mediated inhibition of surfactant and restores the biophysical properties of surfactant. To the best of our knowledge, this study establishes for the first time that (i) SP-D suppresses LPS-mediated NETosis, (ii) NETs inhibit pulmonary surfactant function in the absence of SP-D, and (iii) SP-D can restore NET-mediated inhibition of the surfactant system. Arroyo et al. show that pulmonary surfactant protein-D (SP-D), an innate immune collectin, neutralizes LPS and attenuate LPS-mediated formation of neutrophil extracellular traps (NET) in human neutrophils. This study suggests that SP-D sustains the breathing function of the lung during sepsis by reversing NET-mediated inhibition of lung surfactant. [ABSTRACT FROM AUTHOR]

Within drug development and pre-clinical trials, a common, significant and poorly understood event is the development of drug-induced lipidosis in tissues and cells. In this manuscript, we describe a mass spectrometry imaging strategy, involving repeated analysis of tissue sections by DESI MS, in positive and negative polarities, using MS and MS/MS modes. We present results of the detected distributions of the administered drug, drug metabolites, lipid molecules and a putative marker of lipidosis, di-docosahexaenoyl (22:6)-bis(monoacylglycerol) phosphate (di-22:6-BMP). A range of strategies have previously been reported for detection, isolation and identification of this compound, which is an isomer of di-docosahexaenoic (22:6 n-3) phosphatidylglycerol (di-22:6 PG), a commonly found lipid that acts as a surfactant in lung tissues. We show that MS imaging using MS/MS can be used to differentiate these compounds of identical mass, based upon the different distributions of abundant fragment ions. Registration of images of these fragments, and detected drugs and metabolites, is presented as a new method for studying drug-induced lipidosis in tissues. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "Xenon-Induced Recovery of Functional Activity of Pulmonary Surfactant (In Silico Study)" published in a previous issue of the periodical.

We present broadband vibrational sum-frequency generation (VSFG) spectra of Langmuir-Blodgett monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), and different mixtures of them as model systems of pulmonary surfactants. The systematic study explored the dependence of the vibrational spectra as a function of surface tension and mixture ratio in various polarization combinations. The extremely short acquisition time and the high spectral resolution of our recently developed spectrometer helped minimize sample degradation under ambient conditions throughout the duration of the measurement and allowed the detection of previously unseen vibrational bands with unprecedented signal-to-noise ratio. The dramatically improved capability to record reliable vibrational spectra together with the label-free nature of the VSFG method provides direct access to native lipid structure and dynamics directly in the monolayer. The resulting data deliver quantitative information for structural analysis of multi-component phospholipid monolayers and may aid in the development of new synthetic pulmonary surfactants. [ABSTRACT FROM AUTHOR]

Background: The expression of the NKX2-1 gene and its encoded protein, thyroid transcription factor 1 (TTF-1), plays a role in pulmonary surfactant homeostasis and lung development. NKX2-1 mutations have been associated with neonatal respiratory distress, hypotonia, choreoathetosis and congenital hypothyroidism. These clinical findings have been coined brain-lung-thyroid syndrome, although not all three organs are always involved. While many of these children develop interstitial lung disease, no systematic review of chest high-resolution CT (HRCT) findings has been reported.Objective: To summarize the clinical presentations, pathology and HRCT imaging findings of children with NKX2-1 mutations.Materials and Methods: We identified six children with NKX2-1 mutations, deletions or duplications confirmed via genetic testing at our institution. Three pediatric radiologists reviewed the children's HRCT imaging findings and ranked the dominant findings in order of prevalence via consensus. We then correlated the imaging findings with histopathology and clinical course.Results: All children in the study were heterozygous for NKX2-1 mutations, deletions or duplications. Ground-glass opacities were the most common imaging feature, present in all but one child. Consolidation was also a prevalent finding in 4/6 of the children. Architectural distortion was less common.Conclusion: HRCT findings of TTF-1 deficiency are heterogeneous and evolve over time. There is significant overlap between the HRCT findings of TTF-1 deficiency, other surfactant dysfunction mutations, and pulmonary interstitial glycogenosis. TTF-1 deficiency should be considered in term infants presenting with interstitial lung disease, especially if hypotonia or hypothyroidism is present. [ABSTRACT FROM AUTHOR]

Iron accumulates in the lungs of patients with common respiratory diseases or transfusion-dependent beta-thalassemia. Based on our previous work, we hypothesized that systemic iron overload affects the alveolar region of the lung and in particular the surfactant producing alveolar epithelial type II (AE2) cells. Mice with a point mutation in the iron exporter ferroportin, a model for human hemochromatosis type 4 were compared to wildtype mice (n = 5 each). Lungs were fixed and prepared for light and electron microscopy (EM) according to state-of-the-art protocols to detect subcellular iron localization by scanning EM/EDX and to perform design-based stereology. Iron was detected as electron dense particles in membrane-bound organelles, likely lysosomes, in AE1 cells. AE2 cells were higher in number but had a lower mean volume in mutated mice. Lamellar body volume per AE2 cell was lower but total volume of lamellar bodies in the lung was comparable to wildtype mice. While the volume of alveoli was lower in mutated mice, the volume of alveolar ducts as well as the surface area, volume and the mean thickness and composition of the septa was similar in both genotypes. The thickness of the air-blood barrier was greater in the mutated than in the WT mice. In conclusion, disruption of systemic iron homeostasis affects the ultrastructure of interalveolar septa which is characterized by membrane-bound iron storage in AE1 cells, thickening of the air-blood barrier and hyperplasia and hypotrophy of AE2 cells despite normal total intracellular surfactant pools. The functional relevance of these findings requires further analysis to better understand the impact of iron on intra-alveolar surfactant function. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to understand the clinical characteristics of preterm neonatal necrotizing enterocolitis (NEC) to improve the medical management level.Methods: The clinical characteristics of preterm NEC infants with low birth weight (LBW, ≥ 1500 g) and very low birth weight (VLBW, < 1500 g) were compared. Then, clinical information, including demographics, surgical interventions and morbidity, were collected.Results: A total of 149 preterm NEC infants (60 with VLBW and 89 with LBW) were enrolled. Their median birth weight and gestational age were 1600 g and 31 weeks, respectively. Respiratory support and surfactant therapy were more frequent in VLBW infants (90% vs. 38% and 75% vs. 21.3%) than in LBW infants. In addition, 70.5% of these infants were fed by formula before the NEC occurred. Prematurity-associated morbidities were significantly higher in VLBW infants. Furthermore, 12.8% of all NEC infants died at discharge, and mortality was more prevalent in VLBW infants (21.7% vs. 6.7%). The most frequently received surgeries were enterostomy (n = 58), primary anastomosis (n = 42), and peritoneal drainage (n = 2). Multifocal, localized and pan-intestinal disease occurred in 77.5%, 19.6% and three infants, respectively. Furthermore, postoperative complications occurred more frequently in VLBW infants.Conclusion: The overall mortality was 12.8% for infants who had a larger mean gestational age and birth weight, when compared to that in developed countries. Higher rate of formula feeding might be an important risk factor for NEC development. Furthermore, mortality and morbidities, especially nutrition-associated complications, were more frequent in VLBW infants. [ABSTRACT FROM AUTHOR]

Neonatal lung ultrasound is a novel imaging technique that is gathering growing interest in neonatal intensive care units (NICU). Functional lung ultrasound is able to document the failure of non-invasive respiratory support that often preludes to exogenous surfactant administration for respiratory distress syndrome (RDS) [[1]]. However, there are enough evidence-based data to give surfactant as early as possible (that is, within the first 3 hours of life) [[9]] in preterm neonates affected by RDS treated with continuous positive airway pressure (CPAP) and all guidelines recognize this [[2], [4]]. [Extracted from the article]

This work is devoted to the dynamic properties of adsorption films of pulmonary surfactant and a spread monolayer of dipalmitoylphosphatidylcholine, which is the main component of the mixed surfactant. The surface dilatational elasticity of the aforementioned systems has been determined using a recently proposed approach, which is based on the analysis of a response of a system to large deformations of a surface, and a modified Langmuir trough, which excludes solution leakage under barriers. At low surface tensions (below 30 mN/m) corresponding to those in pulmonary alveoles, the surface elasticity of a pulmonary surfactant adsorption film is half that of the spread dipalmitoylphosphatidylcholine monolayer. This may, in the former case, be related to the displacement of components with lower surface activity from the surface upon film compression. [ABSTRACT FROM AUTHOR]

Purpose: Pulmonary surfactant (PS) plays roles in promoting the removal of the liquid, host defense, and immune regulation in the tracheal, bronchial, and alveoli epithelium. PS protein expression level can be regulated by oxygen levels and related free radicals. Obstructive sleep apnea (OSA) is featured with oxygen free radical production for damaging epithelial tissues and thus may affect PS production. The study was to explore the relationship between PS protein and OSA severity.Methods: We collected serum and bronchoalveolar lavage fluid (BALF) samples from 35 OSA patients and 22 healthy subjects. PS-associated proteins and inflammatory factors, including surfactant proteins, HIF-1α, NF-κB, and IL-6, were analyzed. Regression analysis was performed to reveal the relationship between biochemical factors and clinical indexes recorded during PSG monitor.Results: Lower BALF and surfactant protein (except surfactant protein C or SPC) levels occurred in OSA patients (all p < 0.05 compared to control group). A strongly negative correlation was found between surfactant protein with apnea-hypopnea index (AHI) and other sleeping indexes including ODI3 and ODI4. Similar patterns were found in serum samples, which were strongly correlated with BALF counterparts. Surfactant proteins were further found to have negative regression with inflammatory factors such as HIF-1α, NF-κB, and IL-6.Conclusions: This study established the relationship between PS-related protein with severity of OSA, plus their relationship with inflammatory factors. Our results provided possibly novel markers in general circulation for disease evaluation of OSA. [ABSTRACT FROM AUTHOR]

Background: To determine population-based prevalence and disease contribution of phosphatidylcholine synthetic pathway-associated gene variants in a native southern Chinese cohort.Methods: We used bloodspots from 2010 that were obtained from the Guangxi Neonatal Screening Center in Nannning China and included the Han (n = 443) and Zhuang (n = 313) ethnic groups. We sequenced the exons of cholinephosphate cytidylyltransferase (PCYT1B) lysophospholipid acyltransferase 1 (LPCAT1), and cholinephosphotransferase (CHPT1) genes, and analyzed both rare and common exonic variants.Results: We obtained five mutations (G199D, A299V, G434C, Y490C, L312S) with eight alleles in the three candidate genes. The collapsed minor allele frequency for candidate genes was not significantly different between the Han and Zhuang populations (0.0045 vs. 0.0064, respectively, P = 0.725). The combined Han and Zhuang pool collapsed carrier frequency of rare mutation allele was found to be 1.06%, which is much higher than previously reported for the Missouri population (0.1%). Further, we detected six exonic common variants (three in LPCAT1 and three in CHPT1), with three non-synonymous variants (F162S, F341L, M427K) among them. Two of the non-synonymous exonic variants (F341L, M427K) were not found in CHB; F341L was also not previously reported in exome sequencing project.Conclusions: The population-based frequency of mutations in the phosphatidylcholine synthesis pathway-associated genes PCYT1B LPCAT1, CHPT1 is low in southern Chinese newborns and there is no evidence of contribution to population-based disease burden of respiratory distress syndrome. As a population-based study of rare mutations and common variants, this work is valuable in directing future research. [ABSTRACT FROM AUTHOR]

The main goal for the neonatologist is to facilitate the adaptation to extra-uterine life during initial transition, while minimizing lung injury opening and protecting the premature lung from the first breath onwards. An appropriate management from birth should lead to the achievement of an early functional residual capacity (FRC), and the following steps should aim at maintaining an adequate lung volume. To date, different strategies are available to optimize fetal-neonatal transition and promote lung recruitment. New ventilation approaches, such as sustained lung inflation (SLI) and "open lung strategy", well-established ventilation techniques with a more tailored application and less invasive modalities to administer surfactant have been recently introduced in clinical practice with promising results.Conclusions: given the current status of neonatal care, it seems that lung injury and BPD could be reduced with multiple strategies starting early in the delivery room. Literature underlines the importance of a respiratory tailored management of preterm infants from birth and during the whole NICU stay. What is Known: • Experimental and clinical studies have shown that the transition from fetal to adult type cardiorespiratory circulation needs an adequate lung ventilation. An appropriate management in the delivery room should lead to the achievement of an early FRC, and through the following steps, the neonatologist should aim at maintaining an adequate lung volume. • Literature underlines the importance of a respiratory tailored management of preterm infants during the whole NICU stay to maintain the benefits of a successful postnatal adaption. What is New: • Herewith, we describe the most relevant and recent interventions which can be performed from the delivery room to the NICU stay to guarantee an adequate tradition to postnatal life and an effective cardiorespiratory stability. [ABSTRACT FROM AUTHOR]

Poractant alfa (Curosurf) is a natural, porcine-derived surfactant that is well established as an effective and generally well-tolerated agent in the treatment of respiratory distress syndrome (RDS) in preterm infants. The efficacy of poractant alfa in RDS is better than that of early-generation synthetic surfactants, and limited data are available regarding its efficacy versus new-generation synthetic agents. Poractant alfa 200 mg/kg is more effective than poractant alfa 100 mg/kg or bovine-derived beractant 100 mg/kg. Techniques for administering poractant alfa include via an endotracheal tube or less invasive techniques [e.g. less invasive surfactant administration (LISA)] performed during non-invasive ventilation of spontaneously breathing infants via nasal continuous positive airway pressure (CPAP). Administration of poractant alfa 200 mg/kg in early rescue [i.e. fraction of inspired oxygen (FiO) ≥ 0.3] via LISA is associated with increased successful management on continuous positive airway pressure, as well as reductions in the incidence of bronchopulmonary dysplasia (BPD) and death/BPD. [ABSTRACT FROM AUTHOR]

Purpose: Mortality prediction in ARDS is important for prognostication and risk stratification. However, no prediction models have been independently validated. A combination of two biomarkers with age and APACHE III was superior in predicting mortality in the NHLBI ARDSNet ALVEOLI trial. We validated this prediction tool in two clinical trials and an observational cohort.Methods: The validation cohorts included 849 patients from the NHLBI ARDSNet Fluid and Catheter Treatment Trial (FACTT), 144 patients from a clinical trial of sivelestat for ARDS (STRIVE), and 545 ARDS patients from the VALID observational cohort study. To evaluate the performance of the prediction model, the area under the receiver operating characteristic curve (AUC), model discrimination, and calibration were assessed, and recalibration methods were applied.Results: The biomarker/clinical prediction model performed well in all cohorts. Performance was better in the clinical trials with an AUC of 0.74 (95% CI 0.70-0.79) in FACTT, compared to 0.72 (95% CI 0.67-0.77) in VALID, a more heterogeneous observational cohort. The AUC was 0.73 (95% CI 0.70-0.76) when FACTT and VALID were combined.Conclusion: We validated a mortality prediction model for ARDS that includes age, APACHE III, surfactant protein D, and interleukin-8 in a variety of clinical settings. Although the model performance as measured by AUC was lower than in the original model derivation cohort, the biomarker/clinical model still performed well and may be useful for risk assessment for clinical trial enrollment, an issue of increasing importance as ARDS mortality declines, and better methods are needed for selection of the most severely ill patients for inclusion. [ABSTRACT FROM AUTHOR]

Objective: To assess the outcome of a modified method of Minimally Invasive Surfactant Therapy (MIST) therapy where an orogastric tube was used for tracheal catherization to deliver surfactant in preterm newborns less than 34 wk of gestation with respiratory distress syndrome (RDS).Methods: A single centre, prospective observational study was conducted to enroll eligible inborn preterm neonates with gestation age more than 24 wk but less than 34 wk and suffering from RDS to receive surfactant using MIST. Results were compared with a historical cohort of preterms who received surfactant with InSurE (Intubate, Surfactant, Extubate) technique.Results: Sixty four cases in the modified MIST group were compared with a historic cohort of 68 cases in the InSurE group. There were no differences in the requirement of intubation and mechanical ventilation (MV) in the first 72 h but the duration of MV and continuous positive airway pressure (CPAP) were significantly less in modified MIST group. Other neonatal morbidities and mortality rates were similar in either of the groups.Conclusions: The modified MIST technique is an effective method for the treatment of RDS in preterms with better clinical efficacy and comparable outcomes than the more invasive InSurE procedure and deserves further evaluation. [ABSTRACT FROM AUTHOR]

Lung surfactant is a complex mixture of lipids and proteins lining the alveolar epithelium. At the air-liquid interface, surfactant lowers surface tension, avoiding alveolar collapse and reducing the work of breathing. The essential role of lung surfactant in breathing and therefore in life, is highlighted by surfactant deficiency in premature neonates, which causes neonatal respiratory distress syndrome and results in early death after birth. In addition, defects in surfactant metabolism alter lung homeostasis and lead to disease. Special attention should be paid to two important key cells responsible for surfactant metabolism: alveolar epithelial type II cells (AE2C) and alveolar macrophages (AM). On the one hand, surfactant deficiency coming from abnormal AE2C function results in high surface tension, promoting alveolar collapse and mechanical stress in the epithelium. This epithelial injury contributes to tissue remodeling and lung fibrosis. On the other hand, impaired surfactant catabolism by AM leads to accumulation of surfactant in air spaces and the associated altered lung function in pulmonary alveolar proteinosis (PAP). We review here two recent cell therapies that aim to recover the activity of AE2C or AM, respectively, therefore targeting the restoring of surfactant metabolism and lung homeostasis. Applied therapies successfully show either transplantation of healthy AE2C in fibrotic lungs, to replace injured AE2C cells and surfactant, or transplantation of bone marrow-derived macrophages to counteract accumulation of surfactant lipid and proteinaceous material in the alveolar spaces leading to PAP. These therapies introduce an alternative treatment with great potential for patients suffering from lung diseases. [ABSTRACT FROM AUTHOR]

The lipid transporter, ATP-binding cassette class A3 (ABCA3), is a highly conserved multi-membrane-spanning protein that plays a critical role in the regulation of pulmonary surfactant homeostasis. Mutations in ABCA3 have been increasingly recognized as one of the causes of inherited pulmonary diseases. These monogenic disorders produce familial lung abnormalities with pathological presentations ranging from neonatal surfactant-deficiency-induced respiratory failure to childhood or adult diffuse parenchymal lung diseases for which specific treatment modalities remain limited. More than 200 ABCA3 mutations have been reported to date with approximately three quarters of patients presenting as compound heterozygotes. Recent advances in our understanding of the molecular basis underlying normal ABCA3 biosynthesis and processing and of the mechanisms of alveolar epithelial cell dysregulation caused by the expression of its mutant forms are beginning to emerge. These insights and the role of environmental factors and modifier genes are discussed in the context of the considerable variability in disease presentation observed in patients with identical ABCA3 gene mutations. Moreover, the opportunities afforded by an enhanced understanding of ABCA3 biology for targeted therapeutic strategies are addressed. [ABSTRACT FROM AUTHOR]

To treat respiratory distress syndrome, surfactant is currently delivered via less invasive surfactant administration (LISA) or INtubation SURfactant Extubation (INSURE). The aim of this study was to compare the effect of the two delivery methods of surfactant on cerebral autoregulation. Near infrared spectroscopy monitoring was carried out to detect cerebral oxygen saturation (ScO), and the mean arterial blood pressure (MABP) was simultaneously recorded. Of 44 preterm infants included, the surfactant was administrated to 22 via LISA and 22 via INSURE. The clinical characteristics, treatments and outcomes of the infants showed no significant differences between the two groups. The correlation coefficient of ScO and MABP ( r ) 5 min before administration was similar in the two groups. During surfactant administration, r increased in both groups (0.44±0.10 to 0.54±0.12 in LISA, 0.45±0.11 to 0.69±0.09 in INSURE). In the first and second 5 min after instillation, r was not significantly different from baseline in the LISA group, but increased in the first 5 min after instillation (0.59±0.13, P=0.000 compared with the baseline in the same group) and recovered in the second 5 min after instillation (0.48±0.10, P=0.321) in the INSURE group. There were significant differences in the change rates of r between the two groups during and after surfactant administration. Our results suggest that cerebral autoregulation may be affected transiently by surfactant administration. The effect duration of LISA is shorter than that of INSURE (<5 min in LISA vs. 5-10 min in INSURE). [ABSTRACT FROM AUTHOR]

In developing countries, meconium aspiration syndrome (MAS) is an important cause of morbidity and mortality among neonates. The concepts of pathophysiology and management of meconium stained amniotic fluid (MSAF) and meconium aspiration syndrome have undergone tremendous change in recent years. Routine intranatal and postnatal endotracheal suctioning of meconium in vigorous infants is no longer recommended. Recent studies have challenged its role even in non-vigorous infants. Supportive therapy like oxygen supplementation, mechanical ventilation and intravenous fluids are the cornerstone in the management of meconium aspiration syndrome. Availability of surfactant, inhaled nitric oxide, high frequency ventilators and extracorporeal membrane oxygenation has made it possible to salvage more infants with meconium aspiration syndrome. In this review the authors have discussed the current concepts in the pathophysiology and management of MAS. Drugs in trials and future therapeutic targets are also discussed briefly. [ABSTRACT FROM AUTHOR]

Unlabelled: Lung recruitment during high-frequency ventilation (HFV) in preterm infants with respiratory distress syndrome (RDS) has been associated with an increased risk of lung hyperinflation and air leaks. Individualizing the lung recruitment procedure to the severity of lung disease of each patient might reduce these risks. In this prospective cohort study, we evaluated chest X-ray (CXR) characteristics during individualized oxygenation-guided lung recruitment with HFV in preterm infants with RDS, before and after surfactant therapy. Two pediatric radiologists scored radiolucency, the presence of lung hyperinflation, and/or air leaks following lung recruitment during HFV in 69 infants before and 39 infants after surfactant treatment. Following lung recruitment, the median radiolucency score was 2, with 44 (64 %) infants having a score ≤2. Only mild to moderate hyperinflation was seen in 13 (19 %) infants, with no air leaks. After the surfactant, the radiolucency score improved in 62 % of 39 paired CXRs (p < 0.001). Mild to moderate hyperinflation was seen in nine (24 %) patients. During the entire admission, only four (6 %) of the patients developed air leaks.Conclusion: The risk of significant hyperinflation and air leaks is low when using an individualized oxygenation-guided recruitment procedure during HFV in preterm infants with RDS.What Is Known: • Lung recruitment during high-frequency ventilation in preterm infants with respiratory distress syndrome is associated with an increased risk of lung hyperinflation and air leaks. What is New: • The risk of lung hyperinflation and air leaks is low when using an individualized oxygenation-guided lung recruitment procedure during high-frequency ventilation in preterm infants with respiratory distress syndrome. [ABSTRACT FROM AUTHOR]

Background: Rare mutations in surfactant-associated genes contribute to neonatal respiratory distress syndrome. The frequency of mutations in these genes in the Chinese population is unknown. Methods: We obtained blood spots from the Guangxi Neonatal Screening Center in Nanning, China that included Han ( n=443) and Zhuang ( n=313) ethnic groups. We resequenced all exons of the surfactant proteins-B ( SFTPB), -C ( SFTPC), and the ATP-binding cassette member A3 ( ABCA3) genes and compared the frequencies of 5 common and all rare variants. Results: We found minor differences in the frequencies of the common variants in the Han and Zhuang cohorts. We did not find any rare mutations in SFTPB or SFTPC, but we found three ABCA3 mutations in the Han [minor allele frequency (MAF)=0.003] and 7 in the Zhuang (MAF=0.011) cohorts ( P=0.10). The ABCA3 mutations were unique to each cohort; five were novel. The collapsed carrier rate of rare ABCA3 mutations in the Han and Zhuang populations combined was 1.3%, which is significantly lower than that in the United States ( P<0.001). Conclusion: The population-based frequency of mutations in ABCA3 in south China newborns is significantly lower than that in United States. The contribution of these rare ABCA3 mutations to disease burden in the south China population is still unknown. [ABSTRACT FROM AUTHOR]