Congenital diaphragmatic hernia (CDH) is a severe birth defect that is characterized by pulmonary hypoplasia and pulmonary hypertension (PHTN). PHTN secondary to CDH is a result of vascular ...remodeling, a structural alteration in the pulmonary vessel wall that occurs in the fetus. Factors involved in vascular remodeling have been reported in several studies, but their interactions remain unclear. To help understand PHTN pathophysiology and design novel preventative and treatment strategies, we have conducted a systematic review of the literature and comprehensively analyzed all factors and pathways involved in the pathogenesis of pulmonary vascular remodeling secondary to CDH in the nitrofen model. Moreover, we have linked the dysregulated factors with pathways involved in human CDH. Of the 358 full-text articles screened, 75 studies reported factors that play a critical role in vascular remodeling secondary to CDH. Overall, the impairment of epithelial homeostasis present in pulmonary hypoplasia results in altered signaling to endothelial cells, leading to endothelial dysfunction. This causes an impairment of the crosstalk between endothelial cells and pulmonary artery smooth muscle cells, resulting in increased smooth muscle cell proliferation, resistance to apoptosis, and vasoconstriction, which clinically translate into PHTN.
Purpose
To study pulmonary hypoplasia (PH) associated with congenital diaphragmatic hernia (CDH), investigators have been employing a fetal rat model based on nitrofen administration to dams. Herein, ...we aimed to: (1) investigate the validity of the model, and (2) synthesize the main biological pathways implicated in the development of PH associated with CDH.
Methods
Using a defined strategy, we conducted a systematic review of the literature searching for studies reporting the incidence of CDH or factors involved in PH development. We also searched for PH factor interactions, relevance to lung development and to human PH.
Results
Of 335 full-text articles, 116 reported the incidence of CDH after nitrofen exposure or dysregulated factors in the lungs of nitrofen-exposed rat fetuses.
CDH incidence
: 54% (27–85%) fetuses developed a diaphragmatic defect, whereas the whole litter had PH in varying degrees. Downregulated signaling pathways included FGF/FGFR, BMP/BMPR, Sonic Hedgehog and retinoid acid signaling pathway, resulting in a delay in early epithelial differentiation, immature distal epithelium and dysfunctional mesenchyme.
Conclusions
The nitrofen model effectively reproduces PH as it disrupts pathways that are critical for lung branching morphogenesis and alveolar differentiation. The low CDH rate confirms that PH is an associated phenomenon rather than the result of mechanical compression alone.
To determine the global prevalence for congenital diaphragmatic hernia (CDH) and identify CDH-related risk factors.
Using a defined strategy, a systematic review of the literature was conducted ...according to PRISMA guidelines, searching for population-based epidemiological studies to evaluate the prevalence of CDH globally and per country. Studies containing overlapping populations or timeframes were excluded. CDH-related risk factors were calculated by meta-analysis using RevMan5.3 and expressed as risk ratio and 95% confidence interval.
Prevalence: Of 8230 abstracts screened, 30 full-text articles published between 1980 and 2019 were included. The overall prevalence of CDH was 2.3 in 10,000 births (16,710 CDH babies in 73,663,758 livebirths). Risk factors: From 9 studies we found that male sex RR 1.38 (1.05–1.80), p=0.02 and maternal age >35 years RR 1.69 (1.26–2.25), p=0.0004 were associated with CDH. Conversely, maternal black ethnicity resulted as a protective factor RR 0.82 (0.77–0.89, p<0.00001.
This study reveals that there is a worldwide paucity of population-based studies, and those studies that report on prevalence and risk factors come from a small number of countries. The prevalence of CDH varies within and across geographical world regions. The main risk factors for CDH identified are male sex and older maternal age. More epidemiological studies, involving more world regions, are needed to identify possible strategies to help strengthen our understanding of the risk factors, provide clinicians with the tools necessary for prenatal and postnatal counseling, and inform policy makers on how to strategize CDH care in different parts of the world.
Systematic review and meta-analysis.
Level III.
Abstract Background and aims Perinatal cytomegalovirus (CMV) infection is a possible cause or trigger of biliary atresia though clinical evidence is scant. We hypothesised that CMV IgM+ve biliary ...atresia is a separate clinical entity compared to CMV IgM−ve biliary atresia. Methods Prospective single-centre study. 210 infants with histologically confirmed biliary atresia were treated in our institution (Jan. 2004 to Dec. 2011); of these 20 (9.5%) were CMV IgM+ve at presentation. We compared these with 111 infants who were CMV IgM−ve (controls) for clinical features, biochemistry at presentation and outcome following Kasai portoenterostomy (KPE). A blinded comparison of age-matched liver histology was also performed. Data are quoted as median (interquartile range). A P value ≤ 0.05 was regarded as significant. Results Infants with CMV IgM+ve biliary atresia were older at Kasai portoenterostomy (or laparotomy) 70 (60–80) days vs. 56 (44–75)days; P = 0.003 and were more jaundiced 175 (147–224) vs. 140 (121–181) μmol/L; P = 0.002 + with higher AST*287 (157–403) vs. 180 (133–254) IU/L; P = 0.005 and aspartate aminotransferase-to-platelet ratio index 1.1 (0.79–3.0) vs. 0.63 (0.43–0.95) levels. Liver histology : CMV IgM+ve biliary atresia was characterised by a greater degree of inflammation (P < 0.0001) and fibrosis (P = 0.02), whereas CMV IgM−ve isolated biliary atresia had a higher degree of lobular cholestasis (P = 0.001). This effect was independent of the effects of age at KPE. Outcome : CMV IgM+ve biliary atresia had a poorer outcome with a reduced clearance of jaundice (15% vs. 52.2%; P = 0.002), native liver survival (P < 0.0001) and increased mortality (P = 0.002). Conclusions CMV IgM+ve biliary atresia is a distinct clinical and pathological entity with a diminished response to Kasai portoenterostomy.
Necrotizing enterocolitis is a devastating intestinal disease that affects ~5% of preterm neonates. Despite advancements in neonatal care, mortality remains high (30-50%) and controversy still ...persists with regards to the most appropriate management of neonates with necrotizing enterocolitis. Herein, we review some controversial aspects regarding the epidemiology, imaging, medical and surgical management of necrotizing enterocolitis and we describe new emerging strategies for prevention and treatment.
Necrotizing enterocolitis (NEC) is characterized by intestinal injury and impaired mucin synthesis. We recently showed that breast milk exosomes from rodents promote intestinal cell viability, ...epithelial proliferation, and stem cell activity, but whether they also affect mucus production is unknown. Therefore, the aim of this study was to investigate the effects of bovine milk-derived exosomes on goblet cell expression in experimental NEC and delineate potential underlying mechanisms of action. Exosomes were isolated from bovine milk by ultracentrifugation and confirmed by Nanoparticle Tracking Analysis and through the detection of exosome membrane markers. To study the effect on mucin production, human colonic LS174T cells were cultured and exposed to exosomes. Compared to control, exosomes promoted goblet cell expression, as demonstrated by increased mucin production and relative expression levels of goblet cell expression markers trefoil factor 3 (TFF3) and mucin 2 (MUC2). In addition, exosome treatment enhanced the expression of glucose-regulated protein 94 (GRP94), the most abundant intraluminal endoplasmic reticulum (ER) chaperone protein that aids in protein synthesis. Furthermore, experimental NEC was induced in mouse pups by hyperosmolar formula feeding, lipopolysaccharide administration and hypoxia exposure on postnatal days 5-9. Milk exosomes were given with each gavage feed. NEC was associated with ileal morphological injury and reduction in MUC2+ goblet cells and GRP94+ cells per villus. Exosome administration to NEC pups prevented these changes. This research highlights the potential novel application of milk-derived exosomes in preventing the development of NEC in high-risk infants when breast milk is not available.
Congenital Diaphragmatic Hernia (CDH) is a birth defect that is characterized by lung hypoplasia, pulmonary hypertension and a diaphragmatic defect that allows herniation of abdominal organs into the ...thoracic cavity. Although widely unknown to the public, it occurs as frequently as cystic fibrosis (1:2500). There is no monogenetic cause, but different animal models revealed various biological processes and epigenetic factors involved in the pathogenesis. However, the pathobiology of CDH is not sufficiently understood and its mortality still ranges between 30 and 50%. Future collaborative initiatives are required to improve our basic knowledge and advance novel strategies to (prenatally) treat the abnormal lung development. This review focusses on the genetic, epigenetic and protein background and the latest advances in basic and translational aspects of CDH research.
Necrotizing enterocolitis (NEC) is an inflammatory gastrointestinal disease primarily affecting preterm neonates. Neonates with NEC suffer from a degree of neurodevelopmental delay that is not ...explained by prematurity alone. There is a need to understand the pathogenesis of neurodevelopmental delay in NEC. In this study, we assessed the macroscopic and microscopic changes that occur to brain cell populations in specific brain regions in a neonatal mouse model of NEC. Moreover, we investigated the role of intestinal inflammation as part of the mechanism responsible for the changes observed in the brain of pups with NEC.
Brains of mice were assessed for gross morphology and cerebral cortex thickness (using histology). Markers for mature neurons, oligodendrocytes, neural progenitor cells, microglia, and astrocytes were used to quantify their cell populations in different regions of the brain. Levels of cell apoptosis in the brain were measured by Western blotting and immunohistochemistry. Endoplasmic reticulum (ER) stress markers and levels of pro-inflammatory cytokines (in the ileum and brain) were measured by RT-qPCR and Western blotting. A Pearson test was used to correlate the levels of cytokines (ELISA) in the brain and ileum and to correlate activated microglia and astrocyte populations to the severity of NEC.
NEC pups had smaller brain weights, higher brain-to-body weight ratios, and thinner cortices compared to control pups. NEC pups had increased levels of apoptosis and ER stress. In addition, NEC was associated with a reduction in the number of neurons, oligodendrocytes, and neural progenitors in specific regions of the brain. Levels of pro-inflammatory cytokines and the density of activated microglia and astrocytes were increased in the brain and positively correlated with the increase in the levels pro-inflammatory cytokines in the gut and the severity of NEC damage respectively.
NEC is associated with severe changes in brain morphology, a pro-inflammatory response in the brain that alters cell homeostasis and density of brain cell populations in specific cerebral regions. We show that the severity of neuroinflammation is associated with the severity of NEC. Our findings suggest that early intervention during NEC may reduce the chance of acute neuroinflammation and cerebral damage.
Extracellular vesicles (EVs) derived from amniotic fluid stem cells (AFSCs) mediate anti-apoptotic, pro-angiogenic, and immune-modulatory effects in multiple disease models, such as skeletal muscle ...atrophy and Alport syndrome. A source of potential variability in EV biological functions is how EV are isolated from parent cells. Currently, a comparative study of different EV isolation strategies using conditioned medium from AFSCs is lacking. Herein, we examined different isolation strategies for AFSC-EVs, using common techniques based on differential sedimentation (ultracentrifugation), solubility (ExoQuick, Total Exosome Isolation Reagent, Exo-PREP), or size-exclusion chromatography (qEV). All techniques isolated AFSC-EVs with typical EV morphology and protein markers. In contrast, AFSC-EV size, protein content, and yield varied depending on the method of isolation. When equal volumes of the different AFSC-EV preparations were used as treatment in a model of lung epithelial injury, we observed a significant variation in how AFSC-EVs were able to protect against cell death. AFSC-EV enhancement of cell survival appeared to be dose dependent, and largely uninfluenced by variation in EV-size distributions, relative EV-purity, or their total protein content. The variation in EV-mediated cell survival obtained with different isolation strategies emphasizes the importance of testing alternative isolation techniques in order to maximize EV regenerative capacity.
Background
The clinical and plain radiographic differentiation of congenital intrinsic duodenal anomalies (atresia, web, stenosis) from intestinal malrotation is not always clear. Although sonography ...has been documented as an important diagnostic tool in the differentiation of these two entities, its role is still not widely appreciated and it is still not universally utilized in this clinical setting.
Objective
To assess the usefulness of sonographic features of the duodenal and gastric wall in the differentiation of congenital intrinsic duodenal anomalies from midgut malrotation in a large series of neonates and to compare them with other features on abdominal radiographs, ultrasound and upper gastrointestinal series.
Materials and methods
Using the surgical database at our tertiary pediatric hospital, we identified neonates who had surgically proven congenital intrinsic duodenal anomalies or malrotation over a period of 15 years (2000–2015). We reviewed imaging findings in both groups of neonates (blinded to the final diagnosis) with attention to the echogenicity and thickness of the wall of the duodenum and stomach, the relationship between the superior mesenteric artery and vein, the position of the third portion of the duodenum and the presence of the whirlpool sign. Findings were compared between the groups using the unpaired
t
-test and Fisher exact test.
Results
We included 107 neonates in the study, 40 with a congenital intrinsic duodenal anomaly, 49 with malrotation (36 with volvulus) and 18 with a combination of both. Duodenal and gastric wall thickening and hyperechogenicity were significantly more common in the group with a congenital intrinsic duodenal anomaly compared to those with malrotation (
P
<0.0001). Conversely, an abnormal relationship between the superior mesenteric artery and vein, abnormal position of the third part of the duodenum, and the whirlpool sign were significantly more common in neonates with malrotation than in those with congenital intrinsic duodenal anomalies (
P
<0.0001).
Conclusion
Duodenal or gastric wall thickening, and increased wall echogenicity are helpful sonographic features in the differentiation of congenital intrinsic duodenal anomalies from malrotation. Evaluation of the duodenal and gastric wall should thus be added to the features routinely assessed on ultrasound examinations in the clinical setting of suspected duodenal obstruction in the neonate.
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