Nanofibrous scaffolds support a 3D in vitro permeability model of the human intestinal epitheleum

Advances in drug research not only depend on high throughput screening to evaluate large numbers of lead compounds but also on the development of in vitro models which can simulate human tissues in terms of drug permeability and functions. Potential failures, such as poor permeability or interaction with efflux drug transporters, can be identified in epithelial Caco-2 monolayer models and can impact a drug candidate’s progression onto the next stages of the drug development process. Whilst monolayer models demonstrate reasonably good prediction of in vivo permeability for some compounds, more developed in vitro tools are needed to assess new entities that enable closer in vivo in vitro correlation. In this study, an in vitro model of the human intestinal epithelium was developed by utilizing nanofibers, fabricated using electrospinning, to mimic the structure of the basement membrane. We assessed Caco-2 cell response to these materials and investigated the physiological properties of these cells cultured on the fibrous supports, focusing on barrier integrity and drug-permeability properties. The obtained data illustrate that 2D Caco-2 Transwell® cultures exhibit artificially high trans-epithelial electrical resistance (TEER) compared to cells cultured on the 3D nanofibrous scaffolds which show TEER values similar to ex vivo porcine tissue (also measured in this study). Furthermore, our results demonstrate that the 3D nanofibrous scaffolds influence the barrier integrity of the Caco-2 monolayer to confer drug-absorption properties that more closely mimic native gut tissue particularly for studying passive epithelial transport. We propose that this 3D model is a suitable in vitro model for investigating drug absorption and intestinal metabolism

Tryptophan-Accelerated Electron Flow Through Proteins

Energy flow in biological structures often requires submillisecond charge transport over long molecular distances. Kinetics modeling suggests that charge-transfer rates can be greatly enhanced by multistep electron tunneling in which redox-active amino acid side chains act as intermediate donors or acceptors. We report transient optical and infrared spectroscopic experiments that quantify the extent to which an intervening tryptophan residue can facilitate electron transfer between distant metal redox centers in a mutant Pseudomonas aeruginosa azurin. CuI oxidation by a photoexcited ReI-diimine at position 124 on a histidine(124)-glycine(123)-tryptophan(122)-methionine(121) β strand occurs in a few nanoseconds, fully two orders of magnitude faster than documented for single-step electron tunneling at a 19 angstrom donor-acceptor distance

Influence of Ocean Acidification on a Natural Winter-to-Summer Plankton Succession : First Insights from a Long-Term Mesocosm Study Draw Attention to Periods of Low Nutrient Concentrations

Every year, the oceans absorb about 30% of anthropogenic carbon dioxide (CO2) leading to a re-equilibration of the marine carbonate system and decreasing seawater pH. Today, there is increasing awareness that these changes-summarized by the term ocean acidification (OA)-could differentially affect the competitive ability of marine organisms, thereby provoking a restructuring of marine ecosystems and biogeochemical element cycles. In winter 2013, we deployed ten pelagic mesocosms in the Gullmar Fjord at the Swedish west coast in order to study the effect of OA on plankton ecology and biogeochemistry under close to natural conditions. Five of the ten mesocosms were left unperturbed and served as controls (similar to 380 mu atm pCO(2)), whereas the others were enriched with CO2-saturated water to simulate realistic end-of-the-century carbonate chemistry conditions (mu 760 mu atm pCO(2)). We ran the experiment for 113 days which allowed us to study the influence of high CO2 on an entire winter-to-summer plankton succession and to investigate the potential of some plankton organisms for evolutionary adaptation to OA in their natural environment. This paper is the first in a PLOS collection and provides a detailed overview on the experimental design, important events, and the key complexities of such a "long-term mesocosm" approach. Furthermore, we analyzed whether simulated end-of-the-century carbonate chemistry conditions could lead to a significant restructuring of the plankton community in the course of the succession. At the level of detail analyzed in this overview paper we found that CO2-induced differences in plankton community composition were non-detectable during most of the succession except for a period where a phytoplankton bloom was fueled by remineralized nutrients. These results indicate: (1) Long-term studies with pelagic ecosystems are necessary to uncover OA-sensitive stages of succession. (2) Plankton communities fueled by regenerated nutrients may be more responsive to changing carbonate chemistry than those having access to high inorganic nutrient concentrations and may deserve particular attention in future studies.Peer reviewe

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Parent–child-agreement on health-related quality of life and its determinants in patients born with Esophageal Atresia: a Swedish–German cross-sectional study

Background: The aim was to compare parent and child-reported health-related quality of life (HRQOL) of children born with esophageal atresia (EA) and determine factors that affect the level of parent-child agreement. Methods: We included 63 parent-child dyads of children born with EA aged 8-18 from Germany and Sweden. The generic PedsQL 4.0 (TM) questionnaire and the condition-specific EA QOL questionnaire were used to assess children's HRQOL from parents' and children's perspectives. The PedsQL (TM) Family Impact Module was used to assess parental HRQOL and Family Functioning. Results: On an individual level, intra-class correlation coefficients indicated strong levels of parent-child agreement (.61-.97). At the group level, the analyses showed no significant differences between the responses of parents and children. When a disagreement occurred, parents were more likely to rate generic HRQOL lower than the children (19-35%) and condition-specific HRQOL higher than the children (17-33%). Findings of the binary logistic regression analyzes showed that the child's age, gender, and country (Germany vs. Sweden) were significant predictors of parent-child agreement in condition-specific HRQOL. We did not identify any significant variables that explain agreement for the generic HRQOL. Conclusion: The parent-child agreement is mostly good, suggesting that parent-reports are a reliable source of information. However, discrepancies may occur and can be explained by the child's age, gender, and country (Sweden vs. Germany). Both perspectives are essential sources for treating EA patients and should not be considered right or wrong. Instead, this information broadens the perspective on pediatric EA patients

Postoperative morbidity and health-related quality of life in children with delayed reconstruction of esophageal atresia : a nationwide Swedish study

Background In 10–15% of children with esophageal atresia (EA) delayed reconstruction of esophageal atresia (DREA) is necessary due to long-gap EA and/or prematurity/low birth weight. They represent a patient subgroup with high risk of complications. We aimed to evaluate postoperative morbidity and health-related quality of life (HRQOL) in a Swedish national cohort of children with DREA. Methods Postoperative morbidity, age-specific generic HRQOL (PedsQL™ 4.0) and condition-specific HRQOL (The EA-QOL questionnaires) in children with DREA were compared with children with EA who had primary anastomosis (PA). Factors associated with the DREA group’s HRQOL scores were analyzed using Mann–Whitney U-test and Spearman’s rho. Clinical data was extracted from the medical records. Significance level was p &lt; 0.05. Results Thirty-four out of 45 families of children with DREA were included and 30 returned the questionnaires(n = 8 children aged 2–7 years; n = 22 children aged 8–18 years). Compared to children with PA(42 children aged 2–7 years; 64 children aged 8–18 years), there were no significant differences in most early postoperative complications. At follow-up, symptom prevalence in children aged 2–7 with DREA ranged from 37.5% (heartburn) to 75% (cough). Further digestive and respiratory symptoms were present in ≥ 50%. In children aged 8–18, it ranged from 14.3% (vomiting) to 40.9% (cough), with other digestive and airway symptoms present in 19.0–27.3%. Except for chest tightness (2–7 years), there were no significant differences in symptom prevalence between children with DREA and PA, nor between their generic or condition-specific HRQOL scores (p &gt; 0.05). More children with DREA underwent esophageal dilatations (both age groups), gastrostomy feeding (2–7 years), and antireflux treatment (8–18 years), p &lt; 0.05. Days to hospital discharge after EA repair and a number of associated anomalies showed a strong negative correlation with HRQOL scores (2–7 years). Presence of cough, airway infection, swallowing difficulties and heartburn were associated with lower HRQOL scores (8–18 years), p &lt; 0.05. Conclusions Although children with DREA need more treatments, they are not a risk group for postoperative morbidity and impaired HRQOL compared with children with PA. However, those with a long initial hospital stay, several associated anomalies and digestive or respiratory symptoms risk worse HRQOL. This is important information for clinical practice, families and patient stakeholders

Prevalence of mental health problems, associated factors, and health-related quality of life in children with long-gap esophageal atresia in Sweden

Background: Children with long-gap esophageal atresia (LGEA) face a high risk of digestive and respiratory morbidity, but their mental health outcomes have not been investigated. We aimed to identify the prevalence of mental health problems in children with LGEA, associated factors and health-related quality of life (HRQOL). Methods: Twenty-six children with LGEA aged 3–17 were recruited nationwide in Sweden. One of their parents and adolescents aged 11–17 completed information on the child's mental health (Strength and Difficulties Questionnaire), generic (PedsQL 4.0) and condition-specific HRQOL (EA-QOL). Parents gave information on current child symptomatology. Mental health level was determined using validated norms; abnormal≥90 percentile/borderline≥80 percentile/normal. Elevated levels were considered borderline/abnormal. Data were analyzed using descriptives, correlation and Mann-Whitney-U test. Significance level was p < 0.05. Results: Twelve children with LGEA aged 3–17 (46%) had elevated scores of ≥1 mental health domain in parent-reports, whereas 2 adolescents (15%) in self-reports. In parent-reports, 31% of the children had elevated levels of peer relationship problems, with associated factors being child sex male (p = 0.037), airway infections (p = 0.002) and disturbed night sleep (p = 0.025). Similarly, 31% showed elevated levels of hyperactivity/inattention, and associated factors were male sex (p = 0.005), asthma (p = 0.028) and disturbed night sleep (p = 0.036). Elevated levels of emotional symptoms, seen in 20%, were related to swallowing difficulties (p = 0.038) and vomiting problems (p = 0.045). Mental health problems correlated negatively with many HRQOL domains (p < 0.05). Conclusions: Children with LGEA risk mental health difficulties according to parent-reports, especially peer relationship problems and hyperactivity/inattention, with main risk factors being male sex, airway problems and sleep disturbances. This should be considered in follow-up care and research, particularly since their mental health problems may impair HRQOL. Levels of evidence: Prognosis study, LEVEL II