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Fibroblast growth factor (FGF) signaling is known to play an important role in lung organogenesis. However, we recently demonstrated that FGF10 fails to induce branching in human fetal lungs as is observed in mouse. Our previous human fetal lung RNA sequencing data exhibited increased FGF18 during the pseudoglandular stage of development, suggestive of its importance in human lung branching morphogenesis. Whereas it has been previously reported that FGF18 is critical during alveologenesis, few studies have described its implication in lung branching, specifically in human. Therefore, we aimed to determine the role of FGF18 in human lung branching morphogenesis. Human fetal lung explants within the pseudoglandular stage of development were treated with recombinant human FGF18 in air-liquid interface culture. Explants were analyzed grossly to assess differences in branching pattern, as well as at the cellular and molecular levels. FGF18 treatment promoted branching in explant cultures and demonstrated increased epithelial proliferation as well as maintenance of the double positive SOX2/SOX9 distal bud progenitor cells, confirming its role in human lung branching morphogenesis. In addition, FGF18 treated explants displayed increased expression of SOX9, FN1, and COL2A1 within the mesenchyme, all factors that are important to chondrocyte differentiation. In humans, cartilaginous airways extend deep into the lung up to the 12th generation of branching whereas in mouse these are restricted to the trachea and main bronchi. Therefore, our data suggest that FGF18 promotes human lung branching morphogenesis through regulating mesenchymal progenitor cells.

BACKGROUND: Mast cells are involved in many distinct pathological conditions, suggesting that they recognize and respond to various stimuli and thus require a rich repertoire of cell surface proteins. However, mast cell surface proteomes have not been comprehensively characterized. OBJECTIVE: We aimed to further characterize the mast cell surface proteome to obtain a better understanding of how mast cells function in health and disease. METHODS: We enriched for glycosylated surface proteins expressed in mouse bone marrow-derived cultured mast cells (BMCMCs) and identified them using mass spectrometry analysis. The presence of novel surface proteins in mast cells was validated by qPCR and flow cytometry analysis in BMCMCs and peritoneal mast cells (PMCs). We developed a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) gene editing approach to disrupt genes of interest in BMCMCs. RESULTS: The glycoprotein enrichment approach resulted in the identification of 1270 proteins in BMCMCs, 378 of which were localized to the plasma membrane. The most common protein classes among plasma membrane proteins are small GTPases, receptors and transporters. One such cell surface protein is CD98 heavy chain (CD98hc) encoded by the Slc3a2 gene. Slc3a2 gene disruption resulted in a significant reduction in CD98hc expression, adhesion, and proliferation. CONCLUSIONS: Our study indicates that glycoprotein enrichment coupled with mass spectrometry can be used to identify novel surface molecules in mast cells. Moreover, we found that CD98hc plays an important role in mast cell function.

Rationale: The current understanding of human lung development derives mostly from animal studies. While transcript-level studies have analyzed human donor tissue to identify genes expressed during...

Diabetes mellitus, whether preexisting or gestational, poses significant risk to both the mother and the developing fetus. A myriad of potential fetal complications in the setting of diabetic pregnancies include, among others, congenital anomalies, delayed fetal lung maturity, macrosomia, and increased perinatal morbidity and mortality. Congenital anomalies most commonly involve the nervous, cardiovascular, genitourinary, and musculoskeletal systems. Delayed fetal lung maturity, probably secondary to hyperglycemia suppressing surfactant secretion, is a major determinant of perinatal morbidity and mortality. Besides the potential complications encountered during cesarean delivery in macrosomic fetuses, vaginal delivery is also associated with increased risks of shoulder dystocia, clavicular and humeral fractures, and brachial plexus palsy. Maternal complications are related to the increased risk of hypertensive diseases of pregnancy and associated preeclampsia and hemolysis, elevated liver function, and low platelets (HELLP) syndrome, as well as complications encountered at the time of delivery secondary to fetal macrosomia and cesarean delivery. Additional conditions encountered in the setting of maternal diabetes include polyhydramnios, placental thickening, and two-vessel umbilical cord, each of which is associated with adverse fetal and maternal outcomes including fetal growth restriction, preterm labor, placental abruption, and premature rupture of membranes. Imaging plays a vital role in the evaluation of the mother and the fetus and can provide invaluable information that can be used by maternal fetal medicine to manage this patient population effectively. The authors review the pathophysiologic alterations induced by diabetes in pregnancy, discuss the imaging spectrum of diabetic embryopathy, and provide a detailed review of potential associated maternal complications. Online supplemental material is available for this article.©RSNA, 2021.

Introduction Rubinstein-Taybi syndrome (RSTS) is a rare genetic syndrome caused primarily by a mutation in the CREBBP gene found on chromosome 16. Patients with RSTS are at greater risk for a variety of medical problems, including upper airway obstruction and aspiration. Childhood interstitial lung disease (ILD) thus far has not been definitively linked to RSTS. Here we present three patients with RSTS who developed ILD and discuss possible mechanisms by which a mutation in CREBBP may be involved in the development of ILD. Methods Routine hematoxylin and eosin staining was performed on lung biopsy tissue for histological analysis. Immunofluorescent staining was performed on lung biopsy tissue for markers of fibrosis, surfactant deficiency and histone acetylation. Cases 1 and 2 had standard clinical microarray analysis. Case 3 had whole exome sequencing. Bioinformatics analyses were performed to identify possible causative genes using ToppGene. Results CT images in all cases showed consolidated densities overlying ground glass opacities. Lung histopathology revealed accumulation of proteinaceous material within alveolar spaces, evidence of fibrosis, and increased alveolar macrophages. Immunofluorescent staining showed increase in surfactant protein C staining, patchy areas of increased aSMA staining, and increased staining for acetylated histone 2 and histone 3 lysine 9. Discussion Clinical characteristics, radiographic imaging, lung histopathology, and immunofluorescent staining results shared by all cases demonstrated findings consistent with ILD. Immunofluorescent staining suggests two possible mechanisms for the development of ILD: abnormal surfactant metabolism and/or persistent activation of myofibroblasts. These two pathways could be related to dysfunctional CREBBP protein. This article is protected by copyright. All rights reserved.

Millions of patients seek medical attention for diarrhea, vomiting, nausea, and abdominal pain. In the current environment, it is important to recognize that these symptoms may be the only manifestation or may precede more serious systemic complications of COVID-19. Herein, we describe the first case of ischemic colitis (IC) in a young adult who presented with diarrhea and highlight the laboratory pitfalls for patients with COVID-19 presenting with gastrointestinal (GI) symptoms.

In this study, we present two extra-renal pediatric spindle cell neoplasms with epidermal growth factor receptor (EGFR) internal tandem duplications (ITD). Histologically, these tumors demonstrated the same histologic features seen in other tyrosine kinase-altered spindle cell neoplasms, with one case showing abundant adipose tissue with cellular fibrous septae resembling lipofibromatosis and the other case showing fascicles of spindled cells resembling infantile fibrosarcoma. There was variable expression of CD34, S100, and SMA, and all cases were negative for panTRK. This case series adds to our molecular understanding of the spectrum of tyrosine kinase-altered spindle cell neoplasms and represents the first reported examples of EGFR ITDs in extra-renal tumors. The presence of EGFR alterations in the absence of gene fusions represents a potential therapeutic target and necessitates a broader testing panel for this group of tumors.

Pediatric cystic lung lesions have long been a source of confusion for clinicians, radiologists, and pathologists. They encompass a wide spectrum of entities with variable prognostic implications, including congenital lung malformations, pulmonary neoplasms, and hereditary conditions. As our understanding of the developmental and genetic origins of these conditions has evolved, revised nomenclature and classifications have emerged in an attempt to bring clarity to the origin of these lesions and guide clinical management. This review discusses cystic lung lesions and the current understanding of their etiopathogenesis.

Summary Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of an ongoing pandemic, with increasing deaths worldwide. To date, documentation of the histopathological features in fatal cases of the disease caused by SARS-CoV-2 (COVID-19) has been scarce due to sparse autopsy performance and incomplete organ sampling. We aimed to provide a clinicopathological report of severe COVID-19 cases by documenting histopathological changes and evidence of SARS-CoV-2 tissue tropism. Methods In this case series, patients with a positive antemortem or post-mortem SARS-CoV-2 result were considered eligible for enrolment. Post-mortem examinations were done on 14 people who died with COVID-19 at the King County Medical Examiner's Office (Seattle, WA, USA) and Snohomish County Medical Examiner's Office (Everett, WA, USA) in negative-pressure isolation suites during February and March, 2020. Clinical and laboratory data were reviewed. Tissue examination was done by light microscopy, immunohistochemistry, electron microscopy, and quantitative RT-PCR. Findings The median age of our cohort was 73·5 years (range 42–84; IQR 67·5–77·25). All patients had clinically significant comorbidities, the most common being hypertension, chronic kidney disease, obstructive sleep apnoea, and metabolic disease including diabetes and obesity. The major pulmonary finding was diffuse alveolar damage in the acute or organising phases, with five patients showing focal pulmonary microthrombi. Coronavirus-like particles were detected in the respiratory system, kidney, and gastrointestinal tract. Lymphocytic myocarditis was observed in one patient with viral RNA detected in the tissue. Interpretation The primary pathology observed in our cohort was diffuse alveolar damage, with virus located in the pneumocytes and tracheal epithelium. Microthrombi, where observed, were scarce and endotheliitis was not identified. Although other non-pulmonary organs showed susceptibility to infection, their contribution to the pathogenesis of SARS-CoV-2 infection requires further examination. Funding None.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal lung developmental disorder caused by the arrest of fetal lung formation, resulting in neonatal death due to acute respiratory failure and pulmonary arterial hypertension. Heterozygous single-nucleotide variants or copy-number variant (CNV) deletions involving the FOXF1 gene and/or its lung-specific enhancer are found in the vast majority of ACDMPV patients. ACDMPV is often accompanied by extrapulmonary malformations, including the gastrointestinal, cardiac, or genitourinary systems. Thus far, most of the described ACDMPV patients have been diagnosed post mortem, based on histologic evaluation of the lung tissue and/or genetic testing. Here, we report a case of a prenatally detected de novo CNV deletion (~0.74 Mb) involving the FOXF1 gene in a fetus with ACDMPV and hydronephrosis. Since ACDMPV is challenging to detect by ultrasound examination, the more widespread implementation of prenatal genetic testing can facilitate early diagnosis, improve appropriate genetic counselling, and further management.

Oxygen supplementation in preterm infants disrupts alveolar epithelial type 2 (AT2) cell proliferation through poorly understood mechanisms. Here, newborn mice are used to understand how hyperoxia stimulates an early aberrant wave of AT2 cell proliferation that occurs between Postnatal Days (PNDs) 0 and 4. RNA-sequencing analysis of AT2 cells isolated from PND4 mice revealed hyperoxia stimulates expression of mitochondrial-specific methylenetetrahydrofolate dehydrogenase 2 and other genes involved in mitochondrial one-carbon coupled folate metabolism and serine synthesis. The same genes are induced when AT2 cells normally proliferate on PND7 and when they proliferate in response to the mitogen fibroblast growth factor 7. However, hyperoxia selectively stimulated their expression via the stress-responsive activating transcription factor 4 (ATF4). Administration of the mitochondrial superoxide scavenger mitoTEMPO during hyperoxia suppressed ATF4 and thus early AT2 cell proliferation, but it had no effect on normative AT2 cell proliferation seen on PND7. Because ATF4 and methylenetetrahydrofolate dehydrogenase are detected in hyperplastic AT2 cells of preterm infant humans and baboons with bronchopulmonary dysplasia, dampening mitochondrial oxidative stress and ATF4 activation may provide new opportunities for controlling excess AT2 cell proliferation in neonatal lung disease.

Lung disease in childhood encompasses entities and pathologic patterns that differ significantly from those found in the adult lung. These distinctions are particularly apparent in infants and young children, who are likely to present early in life with congenital lung malformations, disorders of lung development and genetic conditions affecting lung function and homeostasis. This article will highlight the pathology of lung disorders characteristic to the pediatric age group, particularly those which present in infancy and within the first few years of life.

Congenital anomalies of the spine are associated with substantial morbidity in the perinatal period and may affect the rest of the patient's life. Accurate early diagnosis of spinal abnormalities during fetal imaging allows prenatal, perinatal, and postnatal treatment planning, which can substantially affect functional outcomes. The most common and clinically relevant congenital anomalies of the spine fall into three broad categories: spinal dysraphism, segmentation and fusion anomalies of the vertebral column, and sacrococcygeal teratomas. Spinal dysraphism is further categorized into one of two subtypes: open spinal dysraphism and closed spinal dysraphism. The latter category is further subdivided into those with and without subcutaneous masses. Open spinal dysraphism is an emergency and must be closed at birth because of the risk of infection. In utero closure is also offered at some fetal centers. Sacrococcygeal teratomas are the most common fetal pelvic masses and the prognosis is variable. Finally, vertebral body anomalies are categorized into formation (butterfly and hemivertebrae) and segmentation (block vertebrae) anomalies. Although appropriate evaluation of the fetal spine begins with US, which is the initial screening modality of choice, MRI is increasingly important as a problem-solving tool, especially given the recent advances in fetal MRI, its availability, and the complexity of fetal interventions.

Down syndrome (DS) is one of the most prevalent chromosomal abnormalities worldwide, affecting 1 in 700 live births. Although multiple organ systems are affected by the chromosomal defects, respiratory failure and lung disease are the leading causes of morbidity and mortality observed in DS. Manifestations of DS in the respiratory system encompass the entire lung starting from the nasopharynx to the trachea/upper airways to the lower airways and alveolar spaces, as well as vascular and lymphatic defects. Most of our knowledge on respiratory illness in persons with DS arises from pediatric studies; however, many of these disorders present early in infancy, supporting developmental mechanisms. In this review, we will focus on the different lung phenotypes in DS, as well as the genetic and molecular pathways that may be contributing to these complications during development.

We study how chaos, introduced by a weak perturbation, affects the reliability of the output of analog quantum simulation. As a toy model, we consider the Lipkin-Meshkov-Glick (LMG) model. Inspired by the semiclassical behavior of the order parameter in the thermodynamic limit, we propose a protocol to measure the quantum phase transition in the ground state and the dynamical quantum phase transition associated with quench dynamics. We show that the presence of a small time-dependent perturbation can render the dynamics of the system chaotic. We then show that the estimates of the critical points of these quantum phase transitions, obtained from the quantum simulation of its dynamics, are robust to the presence of this chaotic perturbation, while other aspects of the system, such as the mean magnetization are fragile, and therefore cannot be reliably extracted from this simulator. This can be understood in terms of the simulated quantities that depend on the global structure of phase space vs. those that depend on local trajectories., Comment: 13 pages, 7 figures

OBJECTIVE. The purpose of this article is to describe the imaging findings associated with complex fetal abdominal wall defects and provide an algorithmic method for arriving at a final diagnosis. CONCLUSION. Fetal ventral abdominal wall defects are a complex group of conditions with a broad spectrum of associated multisystem anomalies and manifestations. Correct characterization and classification of these defects require not only familiarity with imaging findings but also a systematic approach to avoid diagnostic confusion.

Childhood interstitial lung disease (chILD) comprises a spectrum of rare diffuse lung disorders. chILD is heterogeneous in origin, with different disease manifestations occurring in the context of ongoing lung development. The large number of disorders in chILD, in combination with the rarity of each diagnosis, has hampered scientific and clinical progress within the field. Epidemiologic and natural history data are limited. The prognosis varies depending on the etiology, with some forms progressing to lung transplant or death. There are limited treatment options for patients with chILD. Although U.S. Food and Drug Administration-approved treatments are now available for adult patients with idiopathic pulmonary fibrosis, no clinical trials have been conducted in a pediatric population using agents designed to treat lung fibrosis. This review will focus on progressive chILD disorders and on the urgent need for meaningful objective outcome measures to define, detect, and monitor fibrosis in children.

Lethal lung developmental disorders are a rare but important group of pediatric diffuse lung diseases presenting with neonatal respiratory failure. On the basis of histopathological appearance at lung biopsy or autopsy, they have been termed: alveolar capillary dysplasia with misalignment of the pulmonary veins, acinar dysplasia, congenital alveolar dysplasia, and other unspecified primary pulmonary hypoplasias. However, the histopathological continuum in these lethal developmental disorders has made accurate diagnosis challenging, which has implications for recurrence risk. Over the past decade, genetic studies in infants with alveolar capillary dysplasia with misalignment of the pulmonary veins have revealed the causative role of the dosage-sensitive FOXF1 gene and its noncoding regulatory variants in the distant lung-specific enhancer at chromosome 16q24.1. In contrast, the molecular bases of acinar dysplasia and congenital alveolar dysplasia have remained poorly understood. Most recently, disruption of the TBX4–FGF10–FGFR2 epithelial–mesenchymal signaling pathway has been reported in patients with these lethal pulmonary dysplasias. Application of next-generation sequencing techniques, including exome sequencing and whole-genome sequencing, has demonstrated their complex compound inheritance. These data indicate that noncoding regulatory elements play a critical role in lung development in humans. We propose that for more precise lethal lung developmental disorder diagnosis, a diagnostic pathway including whole-genome sequencing should be implemented.

Down syndrome (DS), also known as trisomy 21 (T21), is the most common human chromosomal anomaly. Although DS can affect many organ systems, lung and heart disease are the leading causes of death. An abundance of existing data suggests that lung abnormalities originate postnatally in DS. However, a single report of branching insufficiency in DS has inferred a potential prenatal origin. The histology of T21 fetal lungs (n = 15) was assessed by an experienced pathologist. Spatial differences in cellular phenotypes were examined using immunohistochemistry (IHC). Comprehensive gene expression in prenatal T21 lungs (n = 19), and age-matched controls (n = 19), was performed using high-throughput RNA sequencing (RNAseq) and validated by RT-qPCR. Histopathological abnormalities were observed in approximately half of T21 prenatal lung samples analyzed, which included dilated terminal airways/acinar tubules, dilated lymphatics, and arterial wall thickening. IHC for Ki67 revealed significant reductions in epithelial and mesenchymal cell proliferation, predominantly in tissues displaying pathology. IHC demonstrated that airway smooth muscle was reduced and discontinuous in the proximal airway in conjunction with reduced SOX2. RNAseq identified 118 genes significantly dysregulated (FDR

Bronchopulmonary dysplasia (BPD) is characterized by alveolar simplification, airway hyperreactivity, and pulmonary hypertension. In our BPD model, we have investigated the metabolism of the bronchodilator and pulmonary vasodilator GSNO (S-nitrosoglutathione). We have shown the GSNO catabolic enzyme encoded by adh5 (alcohol dehydrogenase-5), GSNO reductase, is epigenetically upregulated in hyperoxia. Here, we investigated the distribution of GSNO reductase expression in human BPD and created an animal model that recapitulates the human data. Blinded comparisons of GSNO reductase protein expression were performed in human lung tissues from infants and children with and without BPD. BPD phenotypes were evaluated in global (adh5(−/−)) and conditional smooth muscle (smooth muscle/adh5(−/−)) adh5 knockout mice. GSNO reductase was prominently expressed in the airways and vessels of human BPD subjects. Compared with controls, expression was greater in BPD smooth muscle, particularly in vascular smooth muscle (2.4-fold; P = 0.003). The BPD mouse model of neonatal hyperoxia caused significant alveolar simplification, airway hyperreactivity, and right ventricular and vessel hypertrophy. Global adh5(−/−) mice were protected from all three aspects of BPD, whereas smooth muscle/adh5(−/−) mice were only protected from pulmonary hypertensive changes. These data suggest adh5 is required for the development of BPD. Expression in the pulmonary vasculature is relevant to the pathophysiology of BPD-associated pulmonary hypertension. GSNO-mimetic agents or GSNO reductase inhibitors, both of which are currently in clinical trials for other conditions, could be considered for further study in BPD.

Childhood interstitial lung disease (chILD) comprises >200 rare respiratory disorders, with no currently approved therapies and variable prognosis. Nintedanib reduces the rate of forced vital capacity (FVC) decline in adults with progressive fibrosing interstitial lung diseases (ILDs). We present the design of a multicentre, prospective, double-blind, randomised, placebo-controlled clinical trial of nintedanib in patients with fibrosing chILD (1199-0337 or InPedILD; ClinicalTrials.gov: NCT04093024). Male or female children and adolescents aged 6–17 years (≥30; including ≥20 adolescents aged 12–17 years) with clinically significant fibrosing ILD will be randomised 2:1 to receive oral nintedanib or placebo on top of standard of care for 24 weeks (double-blind), followed by variable-duration nintedanib (open-label). Nintedanib dosing will be based on body weight-dependent allometric scaling, with single-step dose reductions permitted to manage adverse events. Eligible patients will have evidence of fibrosis on high-resolution computed tomography (within 12 months of their first screening visit), FVC ≥25% predicted, and clinically significant disease (Fan score of ≥3 or evidence of clinical progression over time). Patients with underlying chronic liver disease, significant pulmonary arterial hypertension, cardiovascular disease, or increased bleeding risk are ineligible. The primary endpoints are pharmacokinetics and the proportion of patients with treatment-emergent adverse events at week 24. Secondary endpoints include change in FVC% predicted from baseline, Pediatric Quality of Life Questionnaire, oxygen saturation, and 6-min walk distance at weeks 24 and 52. Additional efficacy and safety endpoints will be collected to explore long-term effects., We describe the design of #InPedILD, a study of 24 weeks’ nintedanib or placebo on top of standard of care, followed by variable-duration open-label nintedanib in children with interstitial lung disease (ClinicalTrials.gov NCT04093024) #PedILD https://bit.ly/3tC1a7P

We introduce kicked $p$-spin models describing a family of transverse Ising-like models for an ensemble of spin-$1/2$ particles with all-to-all $p$-body interaction terms occurring periodically in time as delta-kicks. This is the natural generalization of the well-studied quantum kicked top ($p$=2)[Haake, Ku��, and Scharf, Z. Phys. B 65, 381 (1987)]. We fully characterize the classical nonlinear dynamics of these models, including the transition to global Hamiltonian chaos. The classical analysis allows us to build a classification for this family of models, distinguishing between $p=2$ and $p>2$, and between models with odd and even $p$'s. Quantum chaos in these models is characterized in both kinematic and dynamic signatures. For the latter we show numerically that the growth rate of the out-of-time-order correlator is dictated by the classical Lyapunov exponent. Finally, we argue that the classification of these models constructed in the classical system applies to the quantum system as well., 14 pages, 6 figures, and appendices. Close to the published version

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a rare lethal lung developmental disorder in neonates due to heterozygous loss-of-function of the mesenchymal transcription factor gene, FOXF1. Interestingly, unlike ACDMPV-causing point mutations in FOXF1 that can be inherited from the mother or father, causative copy-number variant (CNV) deletions arise de novo and almost exclusively on chromosome 16 inherited from the mother (n = 50 vs. n = 3). Here, we describe a fourth case of a de novo paternal CNV deletion encompassing FOXF1, its neighboring long non-coding RNA gene FENDRR, and their distant lung-specific enhancer, identified in a 21-week-old fetus with tetralogy of Fallot, gastrointestinal and genitourinary abnormalities, a single umbilical artery, and patchy histopathological findings of ACDMPV in autopsy lung. We also review the ACDMPV-causative CNV deletions detected prenatally and propose that the majority of paternal deletions manifest with more severe additional non-lung abnormalities.

Neonates and young children are likely to present early in life with cystic lung disease that is developmental in origin. Distinguishing focal malformations from diffuse lung disease is essential given the implications for prognosis and treatment. A multidisciplinary approach to these disorders, with clinical, radiographical, pathological, and frequently molecular evaluations, is required to arrive at a specific diagnosis. This chapter reviews the spectrum of congenital and developmental entities presenting as cystic lung disease in children including discussion of proposed pathogenesis as well as genetic and neoplastic implications.

Pediatric cystic lung lesions have long been a source of confusion for clinicians, radiologists, and pathologists. They encompass a wide spectrum of entities with variable prognostic implications, including congenital lung malformations, pulmonary neoplasms, and hereditary conditions. As our understanding of the developmental and genetic origins of these conditions has evolved, revised nomenclature and classifications have emerged in an attempt to bring clarity to the origin of these lesions and guide clinical management. This review discusses cystic lung lesions and the current understanding of their etiopathogenesis.

Background Alveolar capillary dysplasia (ACD) is a rare cause of severe pulmonary hypertension and respiratory failure in neonates. The onset of ACD is usually preceded by a short asymptomatic period. The condition is refractory to all available therapies as it irreversibly affects development of the capillary bed in the lungs. The diagnosis of ACD is based on histopathological evaluation of lung biopsy or autopsy tissue or genetic testing of FOXF1 on chromosome 16q24.1. Here, we describe the first two Polish patients with ACD confirmed by histopathological and genetic examination. Case presentation The patients were term neonates with high Apgar scores in the first minutes of life. They both were diagnosed prenatally with heart defects. Additionally, the first patient presented with omphalocele. The neonate slightly deteriorated around 12th hour of life, but underwent surgical repair of omphalocele followed by mechanical ventilation. Due to further deterioration, therapy included inhaled nitric oxide (iNO), inotropes and surfactant administration. The second patient was treated with prostaglandin E1 since birth due to suspicion of aortic coarctation (CoA). After ruling out CoA in the 3rd day of life, infusion of prostaglandin E1 was discountinued and immediately patient’s condition worsened. Subsequent treatment included re-administration of prostaglandin E1, iNO and mechanical ventilation. Both patients presented with transient improvement after application of iNO, but died despite maximized therapy. They were histopathologically diagnosed post-mortem with ACD. Array comparative genomic hybridization in patient one and patient two revealed copy-number variant (CNV) deletions, respectively, ~ 1.45 Mb in size involving FOXF1 and an ~ 0.7 Mb in size involving FOXF1 enhancer and leaving FOXF1 intact. Conclusions Both patients presented with a distinct course of ACD, extra-pulmonary manifestations and response to medications. Surgery and ceasing of prostaglandin E1 infusion should be considered as potential causes of this variability. We further highlight the necessity of thorough genetic testing and histopathological examination and propose immunostaining for CD31 and CD34 to facilitate the diagnostic process for better management of infants with ACD.

Background Diffuse intrinsic pontine glioma (DIPG) is a uniformly fatal CNS tumor diagnosed in 300 American children per year. Radiation is the only effective treatment and extends overall survival to a median of 11 months. Due to its location in the brainstem, DIPG cannot be surgically resected. Immunotherapy has the ability to target tumor cells specifically; however, little is known about the tumor microenvironment in DIPGs. We sought to characterize infiltrating immune cells and immunosuppressive factor expression in pediatric low- and high-grade gliomas and DIPG. Methods Tumor microarrays were stained for infiltrating immune cells. RNA was isolated from snap-frozen tumor tissue and Nanostring analysis performed. DIPG and glioblastoma cells were co-cultured with healthy donor macrophages, T cells, or natural killer (NK) cells, and flow cytometry and cytotoxicity assays performed to characterize the phenotype and function, respectively, of the immune cells. Results DIPG tumors do not have increased macrophage or T-cell infiltration relative to nontumor control, nor do they overexpress immunosuppressive factors such as programmed death ligand 1 and/or transforming growth factor β1. H3.3-K27M DIPG cells do not repolarize macrophages, but are not effectively targeted by activated allogeneic T cells. NK cells lysed all DIPG cultures. Conclusions DIPG tumors have neither a highly immunosuppressive nor inflammatory microenvironment. Therefore, major considerations for the development of immunotherapy will be the recruitment, activation, and retention of tumor-specific effector immune cells.

We have tested the efficacy of hydroxypropyl-beta-cyclodextrin (HPBCD) delivered by the nasal route in the mouse model of juvenile Niemann-Pick C1 disease (NPC1), as pulmonary disease has not responded to systemic therapy with this drug. Since mice have no gag reflex, coating of the nasal cavity, with possible access to the brain, would be followed by delivery of HPBCD to the lung. While foamy macrophages, containing stored cholesterol, were found in the Npc1 nmf164 homozygous mice, a marked inflammatory response was found with inhaled HPBCD, both in mutant and wild-type animals. Slight inflammation also occasionally occurred with saline inhalation. There was no difference between the saline-treated, HPBCD-treated, and untreated Npc1 nmf164 homozygous mice for weight, balance beam performance, or coat hanger performance. Interestingly, there was a trend to longer survival in the HPBCD-treated Npc1 nmf164 homozygous mice, which, when combined with the survival times of the saline-treated survivals (each of which was not different), became significant.